I installed a Ghost Rocket in an early (330 prefix) SR9 and it helped a little bit. I went ahead and bought Kit #3 from Galloways which, with the Rocket I already had, made it the same as kit #4. I never got around to installing the springs and plunger when I bought a SR45. I was so impressed with the newer trigger I removed the Rocket from the SR9, sold it and purchased a newer version. It's still not as nice as the 45 so I'll treat it to the springs and Rocket. It's considerably more complicated than just removing the mag disconnect but still not too difficult. There's plenty of videos and printed info on it.