I've owned the HiFiMAN RE0's for about 4 months and it seems like the left cable near the can is somehow defected. The sound would be on and off on the left side when I adjust the cable. I was really sad because these were one of my favorite IEM's to date. I don't consider myself an audiophile and I personally don't believe in burning-in period and such. However, I do spend quite some time listening to music daily (1-2 hours).
I've done some research and it seems like a lot of people are having same problems with the RE0's (or Head-Direct's 'phones in general). I took a decent care of my RE0's but I guess I can say I could've done better.
I also have (or had) Sennheiser CX300, Monster Cable Turbine, Shure SE530, and of course, the broken RE0's. I listened to other cheap and expensive 'phones as well, but none of them really stood out for me. I have Sansa e280 8G, iPod Nano 4th Gen 16G, and the iPhone 4 32G with cMoyBB v2.02 and the iDevice LOD cable. Genre of my choice is usually Alternative.
The reason why I liked the RE0's so much was because of its clarity and detail. I'm a bassist myself and of course, I'd like to listen to pumping and boomy bass in general but these delivered the bass notes very clearly. That being said, I used the cMoyBB v2.02 for its bass boost and it was perfect! Don't get me wrong, I can listen to the RE0's directly connected to my iPod Nano or iPhone and it would still sound amazing. Yes, I am aware that these have higher impedance than the usual IEM's. Maybe that's why I like them so much.
Oh, one more thing. I really like how these don't have any sibilance in my music. I honestly didn't like the SE530's because of their harshness in [ss] sound. It was very fatiguing in my ears. Although the RE0's sound sharp in my ears (not at all bad thing), they still would give me the most pleasure when listening to music.
So I was going to get them fixed or whatnot but I couldn't wait. I ordered a new pair of RE-ZERO's after reading some reviews. I am aware of the adapter and everything (not exactly) about the ZERO's, and you probably could tell already.. I'm very excited!
How do you guys like your ZERO's?? :)