The trigger resistance measured out of the box was 6.5 lbs. After two range trips and some dry firing, it now consistently measures around 6 lb 4 oz. This comfirms my suspicion that M&P triggers are actually lighter than that of the Glock 22 with me or most other Glocks I've shot, since actual measured trigger pull of Glock 22 was over 7 lbs in my experience. At fist, the trigger was gritty. However, the pull from the position where the slack as taken out to firing point did smooth out after a few hundred rounds and some dry firing. Now it feels closer to that of a PPQ, however it's not as light or smooth. There was a rumor about S&W putting in a trigger with more tactile reset, but that was not the case with the one I have.
M&P's slide length is almost identical to Glock 22's slide length. However, the rear grip area position of M&P is more forward in relation to the slide compared to that of a Glock 22. This has two advantages. It makes the overall dimension smaller. Also, from a concealment stand point, when you place your hand on the grip on a holstered M&P, your hands would be lower, giving you the advantage of a lower ride holster when you are using a holster that rides the same height. I was able to make this comparison because the M&P just happens to fit in a Galco holster for Glock 22. That means less motion for draw. The degree of motion was not significant for me, but I felt significantly less strain for me to reach the grip on a holstered M&P because I did not have to reach as high or twist my upper body as much. M&P is slightly taller, but the difference is almost negligible once the magazines are plugged in.
The trigger guard is larger. This would significantly aid in comfort for using the pistol with gloves.
The room within the trigger guard is both longer and taller. However, this couple with the issue of frame rail being sorter than a Glock 22 made use if X300 a problem: X300 configured to fit a Glock 22 rail would not go deep enough on M&P's rail to engage it without modification.
The standard 3 dot sights are very practical for me. The iron sight picture was clear. The serrated rear sight rear surface appeared great. Sights as set from the factory was good zero wise and did not need any adjustments. Horizontal zero was acceptable. Inclination setting wise, I was concerned because it was hitting slightly low at 10m. I was worried that I would have to aim higher at longer distance. It turned out that the pistol's sight is set so that the sight reference line and trajectory intersected at longer distance. So, when I was shooting at 35~ 50 yard target, I just had to aim center with the sights. This is all using a traditional sight picture, meaning my sight reference point was at the top center of the front sight. That was using 165 gr winchester white box and Speer Gold Dot ammunition. Speer ammo was only shot up to 15m, but it was hitting the same spot as the winshester at same range, so it would be safe to assume that it would have the same zero effect.
Ergonomics are great for me. Compared to Glock 22, the grip is thinner at some point and thicker at some other points. The grip around the height of web of hand area and index finger is about 2mm thinner. Also, the distance from web of hand area of the rear surface of the grip and the trigger is shorter. This gave me greater control of the trigger. The grip swell portion is thicker than Glock22, even with the small grip panel. The grip contour of small and medium size grip panel seen from side is nearly identical. The difference between small and medium size grip panel is mostly in the swell to the side. The large size grip panel do change the trigger reach. I have good trigger reach with all three panels.
I went with the small one. The reason is that I don't need a large swell, and more available trigger reach is preferable in case I need to wear gloves, etc. I might end up in a situation where I need more trigger reach, due to situations such as having forced to grip a pistol in an awkward manner, and I want it available when I do.
I don't have a Ransom Rest, so I don't have a definitive data on accuracy. However, judging from shooting steel targets at 35~50 yards, I seems sufficient for getting head shots at 25m.
