I am selective about what I buy from them. But I will tell you that my 1/4" angle grinder is probably 10 years old. I oil it when I remember (what was I talking about?) It's been dropped. It is in a constant shower of sparks when I am working with it. My air is not that dry. It has a catch in it that will occasionally require me to rotate the disc backwards about a quarter turn before proceeding. It doesn't owe me a dime. Best $10 I ever spent.
So, I have bought several air tools from them. The bad - the 1/4" straight die grinder doesn't have any power. It runs fine and I am probably expecting too much from it. I would guess for polishing it would be great. It won't handle a 3 inch cut-off wheel. The air saw is a bit temperamental. The planishing hammer requires a few improvements but otherwise is great.
The good - besides the angle grinder, I have two of the cut-off wheels, the ones with the metal guards. One has one wheel on it for cutting and the other has two for grinding weld proud. Both work great. The air powered shear. The air ratchet. The english wheel. The bead roller (I did reinforce it). The 1/2 inch drill motor. The 4" and 4-1/2" grinders (the $20 ones - stay away from the $10 ones).