Handguns? I have three of them; a Glock 29, a Glock 22, and a Smith and Wesson 442 revolver.
As for pistol markers, I would say what would generally apply to a handgun would apply to a paintball pistol. You are going to be limited drastically in range to less than about 20ft on average, you are going to be limited in capacity to 10 rounds or less, your accuracy is going to be greatly reduced, and you air source is going to be limited to 12g CO2 canisters that will on average last only 40 rounds. As in the real world, a pistol makes a great backup do to size and quick access, but for general purpose I would say not to use it as a primary unless you really want to challenge yourself. I've heard of real ballsie people using two high end pistols as their primaries, but you'd have to be really good to get anywhere with that setup.
Also, a good and useable pistol marker is going to run you over $200. I have a 32 Degrees PT Extreme marker that I bought years ago and it was about $150 and it is medicore at best. I saw a nice one at the local shop last week that was about $240 and held both the balls and the 12g in the removeable magazine and the magazine could be removed without the 12g losing it's air.
Hope this helped
