[Audiophile_Apprentice]

I contacted ACS, and you can send your impressions directly.

 

[shoeblade]

I solved some of the sound degradation problems mentioned by doing this: http://www.head-fi.org/t/592088/how-to-make-your-er4-custom-iem-tips-sound-much-better

 

[mchang]

Interesting mod, shoeblade. Thanks for sharing.
 
For those still wondering whether to go with Ety customs, check out my recent assessment: http://www.head-fi.org/t/520892/etymotic-hf3-review/60#post_8084043
 
For those not up for reading a bunch, I currently echo the earlier comment to save the $100 and buy lots of Shure olives.