I've bought, fixed, sold,tested, and used thousands of impact wrenches. Just depends on what you're looking for in one. This is what I have seen.....You want torque and smallest ( shortest) 1/2" out there and a well made tool, Cornwell CAT4150, AKA Napa 6-1123. You want cheap and reliable and pretty decent torque, IR 231C. You want loud and unpredictable quality, Snap-On MG725. Want torque, flimsy tip valves and rotor outputs that are too small and will probably break eventually, ( I've seen a bunch of them) IR 2135timax. Quiet and lots of torque and very smooth, Nitrocat 1200K, they do wear out hammer pins faster than twin hammer impacts though. Aircats are twin hammer designs. The Matco MT2769 is crazy strong, can't say as to the quality of it at this point, direction buttons feel very cheap to me on that model. IR2235 looks to be better built that the 2135 from what I can see, haven't had one yet though.
For 3/4" impact I wouldn't hesitate on the IR 2145qimax, well built wrench. IR 261 is stout as well. Aircat 1600th looks well built, And the shortest one and super strong the Cornwell CAT3125, AKA Napa 6-1125, my favorite.
My pick is the CAT4150 or 1200K, or quite possibly the IR 2235, or MT2769. for 1/2"
I know some people gonna get there ******* in a wad, but this is JMO and my recommendation, after all that's pretty much what recommendations are.