It's cheap and Head-Fi regulars tend to gravitate towards more expensive, usually better, IEMs.
I haven't heard GR99 itself, it's supposedly somewhat unlike other VSonic IEMs. VSonic unfortunately isn't directly available in Europe, as opposed to their competitor brand, Brainwavz.
I have heard NE-600M though vs NE-700M and they're close enough.
Hmm. I do agree that ER4S is one of the fastest and least resonant drivers out there, but I find the signature to be doing them a huge disservice, with a large 2-4kHz boost. It also shares the lack of bass impact with most other balanced armatures.
Etys were made for KEMAR with small pinnae, which is not considered the most accurate one. (I had some nice paper on HAT simulators somewhere. KEMAR is best, but with large pinnae.)
Edited by AstralStorm - 11/1/12 at 7:14am