It would probably be best to call each vendor and ask them why you should get their turbo instead of someone else's. I think the main difference would be between a stock HX40 not being perfectly balanced, and the various vendor's turbos being balanced as perfectly as humanly possible. I have the HX40 by Bell Turbo and it has seen 45 psi fairly regularly, 35 psi daily and it has held up with no problems. Some have blown stock HX40s the first time they hit 45 psi.