You can get consistent air pressure at the tool if your compressor and gauges are up to spec.
Now of course all powered tools degrade over time (both pneumatic and electric) and you fancy-schmancy electric impact wrench fan boys will be saddened to hear your electric tool is choochin less and less as it ages. The electric motors just wear out--the motor brushes go kaput, bearings and bushings start to get rough. Most of these cordless drills and impact guns are Chinesium and basically disposable.
I don't use mine for tightening. I use my hands (no finer tool in the world) and a torque wrench. Those guys that can tighten to spec via "ugga dugga" alone are god-level unicorns.