To me, the noreve design looks much more simple and elgant. Also making the case look a little slimmer. Overall, I would much rather get the iRiver case. The iRiver cases look quite simple kind of like the noreve case.
The misticaudio case seems a little "rugged" to me based on the pictures. (The threads are protruding from the ends on the first picture. Others are fine. Maybe that's why it appears the quality is more poor than noreve; they actually include a close up.) A bit more bulky, as it would seem? Well, I guess because it has the extra screen protection part. I don't know. I think the design with the whole extended forked belt seems a little bit overdone. Creativity is good, but I'd much prefer simplicity and width.