Before I got my Glock I was like you. My carry pistol before my current Glock was an M&P40c. I went from a 1911 to the compact for the weight reduction. I had a hard time adjusting to the .40 after being a .45 ACP guy all my life. I traded the S&W in for a Glock 36. Never looked back. I now carry a light, compact, easy to conceal .45. It is dependable, shoots like a dream out of the box. The only thing I changed was the sights, went to Meprolight night sights. With my old eyes I need the extra ad in low light situations. Trigger pull is in the 4-5 pound range, which is perfect for me. The design of the Gen 4 recoil spring looks heavier, but I've had no problems with shooting and the spring design helps with recoil. Take the plunge. Plastic Fantastic is the way to go.