I currently have a Wagner Power painter and I don't recommend them. They make more of a mess than what they spray on your project.
Here is a tip that many people don't think of. If you happen to have a hand sprayer, like a garden sprayer, 5 gal or less, those work just as well as a regular paint system. Clean up is a bit more simplified too. I'm not sure what the prices are on them, haven't had to buy one in several yrs.