The first M&P I ever fired was a FS 40. I noted the recoil and follow thru was more controllable and quicker than with a Glock. I had been shooting Glock 9mms and 40s of all sizes for 20 years at that point. The M&P was a new design at the time, and the advertised intent was that it was designed around the 40 round. That's probably the reason you don't hear too many complaints about the 40 version, and S&W likely never envisioned the 9 would resurge in popularity the way it has. Anyway, the big problem with the 40 Glocks has been breaking trigger pins and locking blocks. I haven't seen the problem in the Gen 2s, but seemed common in the Gen 3s, regardless of round count. The Gen 4 was introduced to correct the problem, but having shot them, can't say that I noticed any better recoil characteristics. Bottom line with each is how the pistol feels and how you shoot with it. That's the one I'd go with.