I was using my little B&D random orbit polisher as well, and let me tell you, the Porter Cable is a totally different beast. It's basically a power tool, and to be honest, I can't imagine waxing a car without it now.

It was easily the best $200 I spent. I do know that the guys on autopia are recommending a different model, because it comes with a 6lb. weighted head, as opposed to the 5lb. that the 7424 has. What that translates to, I do not know... but I do know that my 7424 has served me well. I know there are better deals to be had on it than ordering it from CMA, but the reason I still ordered it from them is because it comes with the velcro head on it already. I also ordered the pad kit.

What I ordered:

http://www.properautocare.com/porcabuldetm.html

at the bottom, you can see the pad kit is $49 from them. It is HIGHLY worth it, the pads they've picked are great.