1. You need a filtration system. There's dust all over my garage and it's not safe breathing all that shiznit, so I broke down and ordered one from northern tool (I think) off e-bay. It was a couple hundred bucks, but it's got to be better than having a coat of dust on everything in your garage.
2. The gun gets clogged fairly easily if you're like me and blasting old RTV off parts. The trick is to scrape as much of that stuff off as you can before you put it in the cabinet. In the reviews I've read, a few people have replaced the gun with a nice one. I'll do that when this one breaks.
3. As with most Harbor Freight stuff, it's a little short for me. I'm 6'2" and it's about 6 inches too short for me. My back is killing me from bending over to work. I'm eventually going to build a dolly or something for it that will raise it up and make it more comfortable.