I (very reluctantly) got the harbor freight 110lb pressurized blaster.
Tried a bag of 20/40 black diamond through it and it continuously clogged the nozzle using the largest end it came with. Unusuable for that size grit with the nozzle ends it comes with.
Switched over to 40/80 and it works just fine.
Very occassionally clogs up. When it's running low on sand, it starts getting clogged at the sand valve at the bottom of the tank - a quick open/close of the valve frees it up. But definitely a pain in the butt - especially since when you're at the end of 100lbs of sand, you're getting sick of blasting and the last thing you need is constant clogging.
The shutoff stopper on the deadman valve wore away, so now I have a steady stream of sandy air blasting out at a 90 degree angle at all times while not blasting.
But - other than that, it strips my parts down like I want it to.
If I weren't in the middle of several projects, i would have spent the money on a better blaster. I'm kind of a tool snob, and don't like to buy anything but the best.
But - in this case, I feel I've already gotten my $120 worth out of the unit, and it's still going strong.
I've never used a more expensive one, so I can't tell you what the differences are.
I'm sure there ARE differences, but all I'm saying is that if you're on a low budget, this one will get the job done.