I have several Ryobi power tools, which were bought because of their attractive prices. My impression after extensive use of them is, they are OK for light duty jobs.
Makita on the other hand, seems to build higher quality tools. I bought a Makita 9227CX3 Sander-Polisher
as a complete kit a couple seasons ago, for buffing and polishing my boat, and have only great things to say about it . . . outstanding results. It's a powerful, well-made buffer.