Gas powered pistols are the preferred sidearms of most airsofters. They are reliable and easy to use. The gas technology gives them power and realism. It also allows for near instantaneous trigger response time, making them quicker than electric pistols. Utilizing powerful green gas, CO2, or propane, gas is the way to go if you're serious about your airsoft game.
Gas blowback pistols are the most realistic gas powered airsoft guns available. The slide on the gun will shoot back with each shot fired, just like a real handgun. Non-blowback guns do not have this feature, but they are usually less expensive and more gas efficient.