We use the protect IV's. I think they're great and have never had the "bury to the hub" issue mentioned above.
We switched to a similiar Braun IV for a few months but went back to the Protect IV's. The Brauns felt dull going in, (more force to pierce skin and vein, Pt's complained more of pain), were a lot messier in that they didn't block blood flow until you were ready to set up the lock/line, and even after a few months the majority of medics were missing easy IV's.