Early impression and experience. Firstly this is the opinion based on personal preference, honeymoon period and lately the Ety fanboy.
By the way, sorry for my broken English.
Some might say that EVO make Etymotic lose their soul. However, I think EVO is still truly Etymotic soul with leaned toward to consumer market.
Audiophile or Ety-head who love the linear sound and want to upgrade from the ER4SR might disappointed. However for me who enjoy with ER2XR, ER4XR or music lover who isn't bass head should be love EVO.
GOOD
+ Sound signature: Using ER4XR as a base, then add more bass especially sub bass, tone down the treble and expand the soundstage. Overall, EVO sound smoother and thicker than ER4XR.
- Bass having nice texture and rumble.
- Mid I think it's the same with ER4XR.
- Treble having less peak.
- Detail retrieval and micro detail are on the same level as ER4XR. Sometime it was tricked by the expanded stage to make I think something missing but it's still there, just change the position and I lose focus.
+ Soundstage and Imaging: It is the vast improvement in my though.
- The stage expand to around head size (ear to ear) instead of cramped everything in your head on ER4XR. Soundstage, Imaging and layering is superb in my opinion, I can point where the instrument came from, not only from left/right, the upper/lower and front and further can still pinpoint easily. Remind that it's still limited to around the head size level.
- Separation: Another thing the benefit from multi-driver and bigger soundstage. Now every notes and instruments are clearly separated from each other. I switched from EVO to ER4XR everything sound congested and blur.
BAD
+ Cable: BaX cable might be good but it too thin. No support at all when wearing over ear.
+ Weight: Heavy and combine with zero support from cable, it make me feel like it might came off the ear (well, it don't). I frequently have to press it back to feel secure.
+ Accessories: Overall is OK but only 2 replacement filters at this price, ER4 came with better accessories at lower price.
Remark
With the new shell, it can't insert as deep as barrel style and have little room for adjustment. The usual tips that perfect on ER series might not goes well with EVO.