To sum it up, yes it's better to spend a little more money up front and get a decent one. I had a Porter Cable 7424 and used it on about 4 polishing jobs before it kicked the bucket. I ended up buying a Flex 3401VRG and am much happier with it. It's not a cheap polisher but it sure works amazing. If you need to do any heavy cutting it's the one I'd recommend getting for sure as it's forced rotation and won't stop spinning under too much pressure. Works great but you do need to be a little more careful with it. Here's the before and after of what I did on my 65 Nova with the Flex.
When I bought the car:
After:
And no, the car wasn't re-painted. That's strictly polishing.
Rupes is a great option as well. I haven't personally used one on a vehicle but I have checked them out and was considering one when I bought my Flex. There's a ton of guys that use them as well.
Adam's Polishes also has their own line of polishers now that I would consider. I haven't actually seen them in person but the price seems very good especially if you're just getting into the polishing game. Might be worth looking into more. I'm considering buying their 3" polisher to get into the smaller areas that my Flex can't.
Biggest thing is that you obviously want a dual action polisher and not a rotary. From there, I highly recommend Adams Polishes pads and polishes as they work great!
