I just got one of these in the mail yesterday to use on my wheels (non-clear coated aluminum). For large areas, it works pretty well-a lot faster than by hand, and better than cloth polishing wheels. I do recommend using either an air-tool or corded drill-it used the battery in my 19.2 V Craftsman pretty quickly. I had to hit some areas by hand, but it cut my polishing time from 1 hour to 10 minutes, with better results.
If you get the 'As Seen on TV offer', it's a pretty good deal. You get the ball, a 15g tube of polish (about $12.00 retail), 5 trial size packs ($5), a coupon for 2 free trial size packs ($2), a mf cloth (w/ scarey poly-bound edges), and $12 worth of coupons for $19.95. So you get $21 worth of product + $12 in coupons + the mf + the ball-not too bad.