I've got a .40S&W 4.25" barrelled M&P, nice gun, light, but a tad heavier than a Glock 22. The trigger definately take some time to get used too, travel is quite short, but requires alot of force to fire, maybe because I only fired 50 rounds through the gun yet, so it's not broken in.
Magazine safety is a real annoying thing, period.
Slide release is almost impossible to operate, too 'recessed' into the frame. Magazines (OEM) are high polish blued, which is bizzare for a Military or Police application gun, I'd have expected flat black plastic magazines.
Novak sights and 'fish scale' slide serrations are a nice touch on a stock gun, and interchangeable backstraps is a nice addition, ensures that the gun will fit any hands. IMO, the large backstrap is by FAR the most comfortable, more rounded, larger rubberised surface. The long 'beavertail' is a nice extra safety feature to avoid slide pinching, but it does not look very good if you ask me.
The gun is a real joke to disassemble for a striker fired gun, 5 seconds and it's done. Same for reassembly.