Here are a few of my 3/8", 1/2" and my former go-to 3/4" impact wrenches. It represents about 45 years of buying impacts. I particularly like the older angle head impacts -- they are so ergonomic and fit my hand better than any pistol grip wrench I have ever tried. I sold all the pistol grip 3/8" drive models years ago.
Of particular interest are two 40 year old US models. One is the CP 723 3/8" impact in the upper left hand corner of the first pic. Super smooth and powerful American made air tool. I was told it was a rebadged Skil tool, but I also have evidence that it was sold by B&D. The others are 1970's vintage 3/8" models made in Japan --two Rockwell models , one Sun (Rockwell), and one Rockford (Rockwell) and an "Executive" Rodac Japanese Butterfly impact that I use mostly as a nutdriver and sheetmetal screw driver -- works great for metal fab work.
The other interesting impact is the "Red" US made 1/2" Rockwell impact with the "ultra-fine" pressure adjustment screw under the trigger. Most other 1/2" impacts of this type had a rather simple pressure adjustment on the bottom of the handle - like the "Black" US made Rodac in the other pic. Both were purchased in 1973.
The other 1/2" is a HF professional model that I really like -- never has failed to perform. Since purchasing the HF gun, I hardly ever need to use the 3/4" Generic Taiwan 1250ft/lb double hammer impact.