I bought the Resolv 50's as a birthday/Xmas present for a family friend last year. Hooked them up in my home studio to make sure they worked properly (and because I was a little curious!) and they sounded pretty good to me. A little hyped in the mids, but definitely not bad. I'd recommend using a sub with them though, as the bass was a little thin.
Haven't used any of the others though.