To be brutally honest, I wanted these things at first because I thought they looked cool. For recording purposes you could always use a sock or a scrunchie, right? However, after I started using the fretwraps I started to notice a difference while playing. I rarely use them to dampen the strings when playing tapping or things like that (because I rarely do it). 98% of the time it sits above the nut - and that is where I need it.
When I don't have a fret wrap on and play riffs where a lot of muting is required, I can ALWAYS here the bit of strings between the tuners and the nut ringing now due to sympathetic resonance, which I didn't even notice before. The fretwraps clamp down on this phenomenon
So be warned, after you use these things, you'll proably end up needing them afterwards.
The over all quality of the fret wraps is OK, I notice bits of string (from the fretwraps) coming off now and then, when pushing it over the nut. Considering the price though, I think that kind of wear is acceptable. I've never worn one of these things out and I have the feeling they'll keep for quite a while.