Survival JP does a detailed comparison between gas guns powered by HFC-134a (Freon) gas and those using CO2 cartridges, specifically focusing on two Glock 17 Gen 5 models from Tokyo Marui and Baton Airsoft. The comparison covers several key aspects including cost and fuel efficiency, muzzle velocity, recoil performance, grouping (accuracy) at 15m, and initial purchase price. The CO2 model generally proved to be more cost-effective per shot, showed higher and more stable muzzle velocities, exhibited significantly stronger recoil, and surprisingly, demonstrated superior accuracy. While Freon gas guns might have a lower initial purchase cost, he concludes that CO2 guns offer better overall performance in various aspects.