The +2 baseplates are for the full length MecGar 10 rounders that have the dented sides, the new style, not sure they will work with the older mags.
For the crap factory mags (yup I'm bashing a CZ product now), the ones with the 1/3 of the body plastic basepads, CZ Custom makes an aluminum pad, but it suffers from the same problems the plastic one does, popping off when dropped and being a pain the ass to take apart and put back together when you want to. The Henning pads, for the full body mags are also very good, but as Sean mentioned, not happy on concrete or rocks.
the problem with the Tanfo rubber pads is the that they are secured with screws. When I shot my Stock II in IPSC I ended up using Gorilla Glue to hold them onto the baseplates and then drilling a hole through them so I could remove the baseplate easily from the magazine. But I'd have to keep an eye on them as the glue would let go now and then. But if you use the screws, that means every time you want to clean them you have to undo screws. PITA. Why they don't make an overmolded rubber pad like Beretta, Sig and so on, I don't know. It would sell bundles.