Pros: Tiny size, comfortable fit, great selection of tips, beautifully, detailed, smooth and balanced, neutral sound, zero fatigue factor.
Cons: Miserable, non-replaceable cable that inevitably kinks and shorts out.
I have been a home audio buff and proud audiophile snob for decades and have only really gotten back into portable audio gear in recent months. I was looking for a nice pair of audiophile IEM's to replace - on a limited budget - my failing, seven year old Etymotic ER-4P's. I value tonal accuracy and sound-staging, and while I want bass to be present I am not a "bass-head." Oh, and I cannot stand upper-register sibilance and harshness masquerading as "detail."
So, now you know my biases!
After doing lots of research on Head-fi, I ordered a pair of RE-600's on Amazon.com.
Sonically, I was beyond thrilled with them! They "play it right down the middle" as one reviewer put it, with a neutral yet compelling tonal signature and a way with human voices which is positively enchanting. This is one of those "I could listen for hours" 'phones. Wonderful!
Beyond that, the housings are well made and feather light. They are tiny and inconspicuous and a pleasure to wear.
I believe that the RE-600 might have actually been my end-game IEM's, if not for the fact that the lower, cloth-covered cable is incredibly fragile and prone to shorting out. In the process of coiling and uncoiling the cable (that is, taking it out of and putting it into the lovely little zipper case) the cable will develop kinks that cannot be smoothed out. Eventually, one of these kinks will turn into a short that will get worse and worse until the phones are unusable.
Lest you think this is my one-off experience, go to the RE-600 Impressions thread and skip to the most recent 8 or 10 pages, and you will read the complaints of multiple, outraged owners of shorted out RE-600's.
The nice lady who answers the phone at USA Hifiman customer service in New Jersey was unfailingly pleasant and sent me a warranty replacement pair in a reasonable amount of time, but as other owners in the above thread have noted, that's all the company will do. They won't acknowledge the problem and (maddeningly) continue to sell this failure prone "flagship" product at a not-inexpensive price. I ended up selling my replacement pair at a bargain price while making sure the buyer knew what tended to happen to these IEM's.
I'll only add that I review home audio gear on my Audio Blog and have never written a review quite this negative. I only want to spare readers of this review the kind of frustration and disappointment that I and so many others have experienced. I can only hope that Hifiman will get its act together and upgrade this wonderful sounding IEM with a decent and durable cable. I'd buy one in an instant if they did. But as things now stand, I'm avoiding their products, even their prized headphones, because I don't think their behavior vis a vis the RE-600 should be rewarded.
Hope this helps someone!