I've gotten 9 cornies from them. I ordered all of them with new rubber and replaced all the seals. I did replace the poppits on one, though I should have done it for all of them. All the same, only one of them doesn't hold pressure because the poppit doesn't seal properly. It's the gas side so it doesn't bother me, I just keep it hooked up to a gas line.
Overall, a good deal. I figure even if a couple of them don't work out, you still average a better price than any rebuilt price IF you are comfortable ripping them apart.