I think I spent more time cleaning the gun after spraying the primer than I did applying the paint.
I used to have that same issue with my old siphon feed spray gun. But then I bought a 3M Accuspray gun with their PPS system and cleaning the gun is a snap. I use a small squeeze bottle to fill the cup port with thinner and spray it out the nozzle. It just takes a couple times and the gun is clean (also remove the nozzle and wipe down the needle. The paint cup liner just gets tossed away. I'd recommend that to any hobbiest painter.
I do use rattle cans for small jobs.
