Disclosure: Not someone in the audiophile hobby but, I do play instruments and appreciate good sound.

Firstly, I would recommend only the XR version for these for any kind of normal use. These are by far the most technical and detailed dynamic driver IEMs I have come across, if you can get the fit right. They are neutral, balanced, detailed and sound great no matter what song or device you throw at them. I'll get the cons out of the way first as there are very few but they could be dealbreakers for some.

CONS:
- Comfort and Fit: It is an absolute dealbreaker but if you cannot get the comfort and fit right, these are going to sound trash. Also the deep insertion is not for everyone and even for me it is not comfortable for very longer listening sessions. If you cannot try these out, I would recommend you have some experience with either the ETYs triple/double flange tips or maybe purchase their Hearing Protection Earplugs which can come handy in high noise environments too and are significantly cheaper to try just for fit and comfort.
- Imaging and Soundstage: These make you feel like you are on the stage with the musicians (which may not be a bad thing) but due to this you are indeed saturated with the sound and can only tell the left from the right channels and not a detailed imaging how far left or right in terms of instrument placement, which might not be the best choice for things like movies and games.

PROS:
- Size: These are tiny and super light you can pocket them anywhere and this makes them my favourite IEMs on the go.
- Decent build quality: No complaints here, the IEMs and the supplied cables have served me for years and still going.
- Isolation: These passively isolate like nothing else!! Forget ANC, you will not be able to hear the person next to you shouting once these are in and if the fit is right. Best in class!!
- Sound Signature: The XR version to me are the most neutral sounding IEMs with a natural tone and timbre. The bass is punchy but tight and controlled, the mid range is well balanced and detailed and the highs have good clarity. This is neutral or with a mild U sound signature with no crazy peaks or dips which may be considered even boring for some but to me it sounds good not matter what you throw at it. The decay across the board is also very natural and almost fell like you are listening to a good speaker system.
- Easy to Drive: These are about 15ohms so moderately high impedence for an IEM but are very easy to get drive from most devices, because of the deep fit it's more effective with it's lower volume. I have also found very little varience in the sound signature across different devices. However, a better source will definately give you better resolution.

Overall it's an amazing, clean, well-tuned IEM that can almost do it all if the fit works for you. These have been my go to pair for years and still sound amazing even by today's standards and technology. I also would like to mention that I personally prefer the double flange tips more than the triplpe flange, the isolation is just as good if not better and it's a way more comfortable fit for me.

Good!

These are now my favorite pair of IEMs as of now. And to me these are perfect but its not for everybody. Let me start with the cons:
1. Fit: The fit is a make or break for this etys. Though they provide an assortment of eartips in the box. Most of them will hurt your ears as you try to shove them deep in your ears. They provide a pair of foam eartips but its size is intimidating and it ultimately hurts as the eartip is huge but it provides excellent seal and noise isolation. If you decide to buy these and you like them and you feel your ears hurts with the provided eartips then I would suggest you to buy the Comply P series tips
2. Soundstage: The soundstage is not big and feels kind of intimate. Mind you it is not claustrophobic either or non-existent. The presentation here is as if the band/singer is performing for you and you alone. I like that presentation but can be a dealbreaker for somebody. If you are expecting to game seriously with this then they are serviceable. I was playing Hogwart's Legacy with these and I could make out where the footsteps are coming from.
3. Drivability: They are drivable from my oneplus dongle but they truly shine with something that have a bit more woomph to it like my Astell and Kern XB10 and my Laptop.

Now comes the pros:
1. Tuning: They are tuned to be DF (Diffused Field) neutral. The SE is tuned to DF neutral and the XR which I got had a 4-5 db boost in the sub bass which I think makes it more enjoyable. The sound is clean and the tuning is perfect for my tastes. The bass is defined and crisp with some rumble also in some tracks;. The mids are excellent and nothing like the instruments or vocals seems drowned in the mix. There is also 0 and I mean 0 sibilance in the treble region. The tuning is really well done.
2. Detail and Resolution: The detail and resolution is mind blowing here. you will be able to hear instruments in the mix that you may have never heard before. They are highly resolving with 0 driver flex. Even on the busiest of tracks there is 0 distortion. How were they able to achieve all this with a puny 5.8 mm dynamic driver is beyond me.
3. Instrument separation: It is great here. As I said earlier you will be able to hear each and every instrument in the mix and since its tuned to be DF neutral you don't have to do much work to pinpoint those either. You can just hear all the instruments easily. It becomes fun after sometime and going back to my TWS daily drivers during my work week I really miss the etys.
4. Noise isolation: Since they sit so deep inside your ears they often function as an earplug and are able to isolate a huge amount of noise. With the provided foam ear tips these are effectively an ear plug and will eliminate all noise.

Some Notes and Suggestions:
1. Ensure that you have proper seal in both ears while using these. If you are unable to get a good seal or are uncomfortable with the ear tips provided. Buy comply P series foam tips
2. If you are someone who dropped 10k for the very 1st time on an IEM and were immediately disappointed after the 1st time you hear them. Just hang on and listen to them for some time, preferably to tracks you have heard 100s of times and then try going back to a different set. I am saying this because I was honestly disappointed after the 1st time I heard them and now look at me.

This is the 1st time I wrote such a long review because I honestly think these deserve that and they should get some more love than they get in the audiophile community. They are just awesome. I heard about them 1st from Crinacle and then Gizaudio and then read Crin's review and decided to pull the trigger. I was actually shopping for the Hexas but decided to go with this and I am very happy I did.

Also a big thanks to Headphone Zone for bringing these products to us at a reasonable price.

Detailed sound signature with bass

I got the ER2XR's to cut out sound on my commute with its legendary noise isolation. What I wasn't expecting was how good these sounded for just single-BA earphones. Due to the excellent seal, the bass performance is just superb and doesn't bleed at all. In certain recordings, they can sound a bit harsh but they're overall very pleasant to listen to for long periods of time.

They're also surprisingly comfortable. The deep insertion into the ear canal is no joke, but with it comes one of the best fits of any IEM I've ever tried. It stays in there and does not come out, and the eartips are extremely soft and don't irritate your ears at all unless you neglect to clean the tips (they need regular cleaning!).

Very clear sounding headphones. Needed some burnin to show its potential. Superb isolation form ambient sounds.

You won't find anything that even comes close to these. The clarity, technical and tuning is absolutely INSANE for the price.
There is a reason why its still the best IEM at this price point. It even completes beats other IEMs which are far more expensive.

I bought these a long time ago, and then found them a bit uncomfortable. I stopped using them, no issues, got a whole bunch of alternatives.
However, I just lost my Timeless 7Hz, and was looking through my box of earphones and found these again. This time, I took the time to go through the packaging and try out the different fits.
I was surprised that these included the dual flange tips, and not just the triple flanges that ety is notorious for.

After a bit of fiddling and some youtube, I could fit these in perfectly. And boy, the isolation from these is absolutely unbelievable. In some cases, they're better than my Galaxy Bud Pro's ANC.
However, the thing that struck me the most was how good they actually sound. The sound, is as natural as it gets, with just the right amount of base thrown in. A surprise, as the last time I tried the Ety ER4's, they lacked that. But these are another case altogether.
Compared to the new comers, I've owned the 7Hz timeless, Final VR3000, a bunch of TWS, but these seem to be the most neutral of the bunch. I would still prefer the flavour of my Timeless. But these deliver, where a lot of the other options fail.

The build is rock solid, the cable is good. They even give a cleaning kit and some foam tips to go with these, along a nice leather pouch.

Pros :
Best in class noise isolation.
Proper neutral sounding
Good bass
Great accessories
L Plug. I don't know why this is not the standard.

Cons :
The fit is very very subjective. Some people will swear by it, but others cannot tolerate it at all. If you fall into the latter category, you will not be able to use these. If it fits right, then you're in for a treat.

Who is it for ?
If you are like me, and like your audio without all the flavour that manufacturers try to add, then this is for you. This is absolutely the most detailed, neutral IEM's under 20K.

Who should avoid it ?
Is soundstage is important, like for gaming, or need spatial awareness (like when driving), then better look elsewhere. These will absolutely block way too much noise to be able to drive. I drive with IEM's (mostly my Samsungs), but these are just on another level. Because they are not noise cancelling, but noise isolation, they will block anything, and not just specific frequencies (which is great for travel, but a no, for driving).
Or Have smaller ear canals, these will sit very deep into your ears, if you are someone who is not comfortable with that, then better to avoid these.

Note - These are the ER2XR's, the ER2SR's have a slightly lesser base tuning and are closer to the other BA Ety's.