I use them on my cats.
I like them, and the cats don't mind them at all - they're very soft & lightweight so they don't bother the cats to wear, and they stretch all over for safety release.
I'll find one laying around the house every now & then because the cats can pull them off, but that's better than getting hung up in one.
My cats have been wearing their current piano-patterned ones for more than a year now (except for Christmas, when they had on their Christmas collars), and they're just now beginning to show cosmetic wear - the pattern is beginning to show a few tiny cracks, and the edges are beginning to fray from being scratched at. Regular fabric safety-release collars (non-beastie band) last about the same amount of time on my cats - they'll start to fray on the surface after about a year or so. In either case, though, the wear is cosmetic - the collars themselves are still holding up fine. I'll probably replace them soon, though, because I like my crew to look their best.

hope this helps

*edit*
Actually, the only collar that's showing much damage is Mr. Underfoot's (he was sitting on my lap as I posted). The other collars are in perfect condition. I think Mr.'s collar is more worn because he spends a lot of time wrestling with our other big cat Oreo.