Very nice and thoughtful review!  The source comparison was particularly helpful!

Thank you, very helpful!

Thanks for the detailed review. That was a lot to swallow, and if anything, made me even more eager to listen to these myself (hopefully, in two weeks from posting).
Glad you found them neutral, as I'm a big fan of that.

I'd be very interested in how this stack up against STAX sr-002 (Stax estat IEM)
I absolutely love the sr-002, I prefer it over the HD800 in fact.
 
I also own an SR-009, which completely ****s on HD800 in every way (because I invested in a good amp).
 
SR-009 with ANY Stax amp < HD800
SR-009 with any good aftermarket amp > HD800
The level of "good" you get out of the SR-009 depends on how much you're willing to spend.
 
 
"the same way SR009 probably is not going to win anyone over in a direct comparison beside the HD800."
This is an amazing review with plenty of details and thought put into it, but reading this makes me second guess your frame of reference.

Thanks guys, still didn't quiet edit it properly as the flow and grammar glitches are plenty. I will fix it later and respond to comment to the best of my ability.

I'll add that for me the combination of electrostat detail and low distortion and the isolation that these KSE1500s provide is fabulous. Little to no intrusion from ambient noise that you will have to some degree with open electrostat headphones or electrostat speakers (that aren't in a sound-isolated room). 

mmm......good review. Echoes my thoughts as well. I specially subscribe to the view that it is not an end-game portable system but the KSE is an invaluable addition to any serious collection of earphones.

@comzee Rarely do we get the chance to hear SR009 paired with those hard to fine tubes and aftermarket amps. Most of the occasion where I had the opportunity to hear the SR009 it was with their stock amp. Now finding the right amp for HD800 now days has become a much easier task thanks to the numerous amplifiers that has became available.
 
To me Luxman P700U paired with HD800 outclassed the SR009 paired with stock amp. The Luxman 700u and HD800 setup cost less than SR009 and stock amp.
 
What I found HD800 does not scale up with different setup, okay maybe running balance does improve it by some factor however I found what in large HD800 respond well is in how its able to alter its sound when paired with warmer sources/amps. It becomes more engaging while keeping its well loved and respected properties. Now in order to achieve the same with SR009 you have to spend twice the amount just on the amplifier. 

Nice review! How would you compare TH900's to KSE1500? The Shures tickle my interest, but only if I can replace my whole headphone rig with them.

@audionewbi You're correct, it is a considerably more expensive setup. The HD800+Good amp is best bang for buck in the audiophile market, not only that, but top 5 headphones imo. The sr009 with best in class amp is about 10% better in every area for me, but for that 10% you pay legitimately 8k+ more for the setup.
 
Although, I'm an estat fan, so I'm highly considering these. I really gotta find someone that has had long term (at least 100hr+) with the sr-002, to compare to these. I don't think I can pull the trigger on 3k if it might sound only slightly better than Stax $500 offering of estat IEM.

the kse1500, is a totally different animal. you have to just let the music happen. unlike other iem were you feel the need to crank it up! to get better SQ, not so for the kse1500,at low level volume you are transported to other worlds.  you hear detail you never new was there. all the highs. mids. and yes base. it's a complete sound .nothing added . SQ. from my QP1R. comes through clean unmolested by dsp. im in love all over again with my QP1R! and i do wish the there was a more comprehensive manual .  its is easy to over load the kse1500. and get clipping. i use -10db. this info came from headfi. not the manual.thankyou headfi peeps!

@Music junky
Exactly the same happens with Stax SR-002 IEM, the volume listening setting is extremly low, and during listening I go even lower with the volume, as longer I listen too, because is so transparent sound, no other even 8 to 12 driver TOTL CIEM can gave me this ariy feeling.

Looking forward to hear the KSE1500 myself in London today.
Been reading about them so you either love them or pass.
The fact that are so neutral  and the micro details as people describe them is a bonus for me as I like that type of sound signature.
Thank you for the wonderful write up. Great review.
Musicday

wow man, i really enjoy reading your review, great in depth detail comprehensive review. superb, but i am curious about one thing : about chord hugo, all i knew is that hugo got a really wide and depth soundstage, and i allready heard kse1500 myselft, to me kse1500 soundstage was huge. i dont get it,you pair kse1500 with chord hugo, the wide soundstage was gone?

I own a lot of other IEM that have different strength. This is in large is the reason why I have kept a variety of IEM in my possession as I know which one will play well with a specific music. 

For instance for classical music HUGO paired with EX-1000 sounded much wider than same setup with KSE1500. So what is causing the bottle-neck with KSE is that I am used to a much more opener sound and KSE1500 open sound will not improve further paired with HUGO. While the pairing will improve other aspect of sound when it comes to improve the soundstage it can push it as much as KSE1500 can offer. 

As is KSE1500 sounds arguably close to best it can sound. Perhaps the possible bottle neck is the amp module and with better amplification KSE can be a lot better, which has been the case with SR009. This theory will remain a theory till we see some after market product that can allow us to test it. 

My Stax SR-002 review is up: http://www.head-fi.org/products/stax-srs-002-in-the-earspeaker-system-srm-002-sr-002-japan-import/reviews/15135 asap I want to compare them with the Shure KSE1500.

I wanted to get the SRS-002 for a long time. On 2014 STAX teased a release of a new version with a much improved amp and internal DAC but it never came into existence. As is I could not get the 002 to say in my ear and the headband didnt improve much. 

That's true the fit and seal is a big challange for SR-002, I know people the love the sound, but they can't use them. Shure has now opend with the KSE1500 with a a way better form and fit like a regular universal IEM inculding for the tips rolling the door for Stax sound on the go.

great review!  if I read your review first, I do not have to ask you questions because all your answers are within the review!  Thanks!

Can the KSE1500 be used with a Stax amp? Or with ANY other existing electrostatic amp?