This is not exclusive to Airguns since trends of Airguns are highly influenced by what type of Real Steel Pistols are popular to people. This is often based on what people see portrayed in movies and TV Series, and also promoted online. There is for sure an overlap in what is popular and it is hard to say what is influencing what? Is it the popularity of Pistols out in the real world that influences what we see being used in the movies and on TV? Or is it what we see in Movies and TV that influences our choices of pistols out in the real world? Perhaps it is a combination of both?
My list is based on my own personal experience and does not represent the entirety of types of Pistol designs available.
Type: Paintball Gun. Manufacturer:Umarex - T4E. Model:S&W M&P9 M2.0 Materials: Metal & Polymer. Weight: 763 grams (1.7 pounds). Barrel: Smooth bore. Power Source: 1x12 gram CO2. Action: Semi-Automatic with blowback action. Ammo Type: .43 Caliber Paintball or Rubber Ball. Ammo Capacity: 8 Rounds. FPS: 290.
Trigger Pull: The trigger pull on Umarex T4E S&W M&P9 M2.0 .43 Cal. Paintball Pistol feels a lot like a double action trigger mainly because when you pull the trigger the inner barrel travels backwards into the magazine which seals off the barrel form the magazine so less CO2 is wasted going it not the magazine and also placing a paintball round in the barrel. This does make the trigger a little bit longer and heavier than a single action trigger. I believe the internal hammer/striker is engaged from the blowback action.
Build Quality: The build quality of the Umarex T4E S&W M&P9 M2.0 .43 Cal. Paintball Pistol is really very good, metal parts are where you would expect them, the slide, slide catch, barrel, magazine and most internal parts giving the Umarex T4E S&W M&P9 M2.0 .43 Cal. Paintball Pistol a nice near 2 pounds (1.7 pounds) of weight with the magazine in which makes the Paintball version a little heavier than the real steal version (1.54 pounds) but once the real steal version is loaded with a full mag this may even out a bit. The Umarex T4E S&W M&P9 M2.0 .43 Cal. Paintball Pistol does have a polymer frame but again this is normal with todays modern guns and helps keep the weight down. Fit and finish is also very good!
Realism: The Umarex T4E S&W M&P9 M2.0 .43 Cal. Paintball Pistol is a near perfect replica of the real steel S&W M&P9 M2.0 Pistol, from the fully licensed markings to the large .43 caliber diameter barrel. If you placed the Paintball version side by side with the real steel version I doubt you could tell them apart unless you start inspecting it really close up and working the action. You will find that the slide cycle distance is a bit shorter than it would be meaning that when the side catch is engaged the slide does not go as far back as it the real 9mm S&W M&P9 M2.0. Field stripping the Umarex T4E S&W M&P9 M2.0 .43 Cal. Paintball Pistol will requires some tools and pin removal.