It depends upon what you want to do with it and how powerful you need. The HW 45 looks a lot like a Colt 1911, on steroids and is a spring air that has a unique feature in that you can cock it at two different power levels. Spring jump/recoil bothers some people and takes a bit of a learning curve to shoot well. The HW75 is a big single stroke pneumatic, no springs,or recoil to deal with, big, heavy , hard to cock, and accurate. I have a Air Venuri AV 46m a pure 10 M target pistol, expensive, single stroke pneumatic, weird looking but easy to cock and accurate beyond belief. Next step is PCP types, but that requires a pump, manual or an electric compressor and I never wanted to get into that. CO2 is ok, but at end of one of the little cartridges life power drops off rather quickly. Honestly I wish I had bought one of the FWB 65 or 100 models back in the day when they were making them, I did some looking and got some Daisy 777 target pistol, and rebuilt them. The made 3 versions, a 717 747 and the 777, first was real basic, the second had a better barrel and adjustable trigger, and the last has the better barrel a milled steel cocking lever vs stamped, an adjustable trigger and a fantastic all steel adjustable sight. Sight on the first two is plastic and adjustable, but the steel one is really good, even the width of the notch is infinetly adjustable via a little screw. Rebuild is rather easy, a few o rings and they have a foam wiper which I replaced with some split teflon rings, kinda compare to rings in an internal combustion engine, but several to hold a couple of drops of oil to keep the compression cylinder oiled.