http://player.ru/showpost.php?p=765394&postcount=2400 (Colorfly vs. Cowon X5 modded) : Of course, X5 (even modded) is much lighter, smaller; the navigation is easier and it supports more formats (kudos to rockbox devs); battery life time is comparable. Now what about the sound: with Re0 i nearly don't hear a difference between Colorfly and X5, so i had to use Um3x to pick up the details. Colorfly and X5 sound is equally detailed. The difference is in the temper of giving the music. X5 has the very flat SQ, and the colorfly is different on mids: all virtual sound sources are about on the same distance on X5, and on colorfly vocals are farther than everything else.
Well, that's nearly all impressions from actual colorfly owners.