If you buy a Velcro backing plate, DON'T buy a Meguiars! I know it's not something that likely happens to all of their plates, but there's a "not-so-uncommon" problem with the hooks breaking off the plate, rendering it useless. Go with an edge plate....I haven't heard any problems with them. I bought a Megs plate, and it messed up after my first detail. I now have an Edge plate, and haven't had any problems.
It's kind of a running joke....if Meguiars would fix the problem with their backing plates and their clay, EVERYTHING they have would be good.