i had a original set of metal rings from Tyler and i currently have 2 sets of the newer Elite plastic rings. i like the newer rings becuase they're not as thick and i have a small hands. however, they are pretty slick by themselves. i use tennis raquest tape and/or chalk.
im tempted to buy a set of the new power max rings, hey, you can never have too many sets, right?! as of now, i have a set at 7' (pullups, MU's, skin the cats, etc), and a set at 4' (dips, goofing around, etc), and then i could have a set a couple inches off the floor for handstands, pushups, etc. ;)