IR, or CP tools. Hard to go wrong. Most air compressor company branded tools like Comp-Air or Atlas Copco are also pretty good quality. Snap-On, Blue Point, Mac, ARO, all good stuff. I'd be leery of any 1/2" gun that claims 1000lb/ft though. Never had a whole lot of use for an air ratchet, except putting con rod big ends onto compressors before torquing them to final spec. Knuckle busters most of the time. I'd rather have a decent 3/8" impact or a butterfly impact instead. 1/2" gun gets tiring if there's lots to do and you don't need all the torque.
Most Campbell Hausfeld stuff isn't that good, but their bigger 1/2" impact worked ok for me. It's a decent budget tool.