I too use a lot of spray cans. For color, I really like the Testors "one coat" lacquer paints, I wish they made them in nonmetallic colors though. I like the Tamiya sprays too, when I can get them, both of those I use over a duplicolor primer. I wet sand the primer with 600 grit, then sand and polish as needed after the clear is on.
I would say these are the most important details to me:
Clean, clean, clean, wash any and all parts to be painted and let air dry, I'm not the most patient person at times, but this is important.
What is the temp and humidity where you are painting?
Watch the thickness of your coats, heavy coats are much more prone to orange peel. Use lighter mist coats, especially on those testors enamels
Practice on some old junk cabs, and once you find what works for you, stick with it.
I have a few sets here, I have had issues with photobucket so i can't post pics right now. They do not attatch the same as a plastic wheel, there is no way to secure them to the axle and maintain the ablity to roll as the hub is part of the wheel.. As for the other issues, I have not had any. I am not knocking them, overall they are nice for the price.