My old ssac T61 blew oil out the exhaust since the day we put it on. It spooled amazingly quick, but ran out of steam in the quarter mile if you ran above 20 psi. Didn't last too long above 20 psi either, before it vibrated itself to death! Bent shaft, and luckily nothing happened to make it into my engine.
Now I've got a SP71.....No comparison, and no more falling off boost on 20psi.....the best money I spent on my car was for a quality turbo.