speedingpenguin,
There are a couple of other PC quality orbital polishers on the market, but most people here use the PC because of the combination of power, build quality, and price. You might very well have a similar tool at home already (I know I've read here about several people using a Dewalt version of the PC and being very happy with it). However, post the make and model here to get some feedback on whether the tool you are referring to is a true substitute for a PC. Something like the little hand-held random orbital sanders by Black and Decker wouldn't work at all.
As for getting a PC, even if you're not a professional, I highly recommend it. I got mine this past xmas, and am amazed at how much easier polishing is with it. I can also get way better results with it than I can get by hand. Polishing didn't use to be fun, because it was so tiring and I got okay results, nothing spectacular. I have a 7 year old car that wasn't cared for properly at all before I found Autopia (swirls and scratches everywhere). Now, after getting a PC, it looks better than it's looked in years.
John