I have the IR 2135 QTiMax gun, I'm very happy with it now. Reviews were great, it only seemed okay, it didn't seem to be the bolt buster that everybody talked about. I had used some Milton "L" QD fittings I had around to hook it up. Based on comments on the "Garage Journal" site I changed the fittings to the Milton high flow "V" fittings. WoW it is like a different gun!! Before I was tightening lug nuts feeding the gun at 90psi, that would torque the nuts to about 90 ft-lbs. With the change in fittings, anything above 60psi to the gun and I am over 90 ft-lbs on the nuts. What a difference better air flow to the gun makes. No matter what gun you get, make sure you have the best air flow to the gun that you can provide.