The IR titanium series ones are awesome! When I worked at the Ford dealer they bought us lube techs a pair of them (I forget the part number) because our impacts were too loud. The were nice and light, well balanced, and more power than our personal impacts
I have a 1/2" Mac I bought used, looks identical to a regular IR, check Northern tool out, alot of times they have decent deals on them.
I wouldnt bother with Snap On or Mac, like you said, too spendy for only the name, The only reason I bought mine (Mac) was that it was $50 used from the tool truck, seems to be getting a little tired lately, but that happens.
An IR Thunder gun would be sweet too.