I'm not very experienced at painting, but even in my limited attempts I agree with the clean-up crap 100%. Plus I never really know how much paint to mix and always make too much and that stuff is expensive.
I've got two guns, but I prefer to use Duplicolor aerosol in bigger twelve oz cans from NAPA. They adjust the color to a perfect match, not just the VIN number, but the batch number, then use a scanner to adjust to my own truck, finally custom mix the color right at the store, I got the formula. I think they even have it on file.
Yes of course, one could always argue that the spray gun is cheaper to use. It is if you spray larger areas. One could also argue that the pattern is better. Perhaps. I buff the finish down to one thousand grit. They also sell a very nice clear coat which I wet sand down to 5,000 grit. It doesn't take long, then I use a polishing compound.
This picture shows a painted lower bumper and valance which had a very bad scrape. I only painted the damaged area and feathered it out. There is no line left at all between old and new.
There is no real cleanup whenever you spray from a can, no thinners, no solvents, no cleaning the gun and no goofing around adjusting the tip or the spray pattern. There's a little bit of money saved therefore when you clean up. There's a lot of time saved in cleanup too.