I did my fat fives. they don't look horrible but they arnt like drop dead stunning either. huge improvement from what they where. I t does take a reasonable amount of time to get them to look good. like 2+ hours a rim depending on the condition.
For mine i:
started out with an orbital sander and 80 grit to get out big scratches and curb rash.
after that i just progressed through sandpaper, ending at about 1500 grit. If you are serously considering doing this though, make sure you sand in all the same direction or it will look like shit. Make sure you clear them afterwords. Duplicolor makes a rim coat that works great.
Before: (kinda bad picture, but there is clearcoat peel, and some bad rash from previous owner)
After:
On the Car: