[AstralStorm]

Here's some last impressions: 2 months ago, the cable isolation completely hardened and predictably, soon afterwards it cracked. It completely broke near one of the earpieces a week ago.
Hifiman, seriously. All your in-ears do this! Including ancient RE0, RE-272 and RE-600. About the only other cable that failed was a certain specific CIEM one.
Must be something about the insulation material.
 
The microphone was good quality but somewhat poor directivity (grabbed lots of surrounding noise) and loudness.

 

[AstralStorm]

Look into the HiFiMan RE-ZERO. It will probably fit all your needs? Analytical. Detailed. Linear. Comfortable. Stellar performance. These are no joke, and lined up with the description you gave.

http://shop.mapleshadestore.com/mobile/prodinfo.asp?number=REZERO

p.s. You'll thank me later. Oh and the fit and QC is far superior to the fragile RE-400, with similar performance.

QC? Fit and sound? Not really.
RE-ZERO are strongly reverberant (which some might like - it can reduce in-head feel) and the bulky shells are pretty hard to nicely lodge in ears - much less comfortable than OEM RE-300 ones for sure. Very hard to mod as well. Isolation is lower. Microphonics are on par. Cable, is also not superior - my pair hardened a long time ago, but is not broken yet - probably just lucky.
RE-400 is sonically a small improvement over RE-ZERO and can be pushed even more by internal damping. RE-600 is equivalent to RE-400 with increased membrane mass - thus darker sound.
 
If I could pick only one, I'd take RE-400 with a replaced cable and additional damping material inside its shell. RE-272 is too light on bass and slightly less even, though otherwise a very strong contender.
 
Yes, I had almost all of their IEMs - the exception being RE-252, RE-262 and RE-300h - and I've heard all of them at least once.

 

[Saoshyant]

Well...  when the RE300a first came out, I made sure to pick it up and give it a try.  Much to my dismay, I just didn't like the sound.  It occurs to me after the fact that perhaps part of why I didn't like the sound might also have to do with the fact that mine didn't last long before the shell split in two due to an inadequate amount of whatever sealant they used to keep the body together.
 
After awhile, I decided to pick up the RE300h to give it another try, which leads to me listening to them right now.  I had picked up the xDuoo X2 not long ago, and I have to admit for me, this is quite a wonderful pairing.  I'm currently listening to some Radiohead, and the bass of this pairing is marvelous for me.  The RE300h, simply put, is such a fun IEM, which the RE line from the ones I've heard struck me as being more towards analytical.
 
All in all, I'm glad it came to this, because I can tell I'm going to really enjoy what's to come from it.  Now I just hope I can find a pairing that makes the ES100 sing.