I've had 2 CFXes converted to the gas rams, and they shoot and feel a lot better at the shot, than the springs do. I really like the conversion and there's one more CFX I have I'm going to convert. Most likely though, I'll be getting the Theoben gas rams put into my CFXes and taking out the Whisper gas rams I currently have in them. Yes, the Whisper gas rams fit the CFXes; you just have to drift the center spring guide out the middle of the spring retention plate.