The 40 S&W round is going to be a bit snappier compared to the 9mm round. I have carried a 27 for years, it was my first Glock. The M&P advantage over Glock is the grip and adjustable backstraps. This advantage extends over the Gen 4 27, which does have an adjustable back strap, in my opinion.

Suggest you go to your local gun store and hold each side by side. Both will be good shooters.

However, the better move might be to get the full size 9 making ammo management easier and the ability to use the 17 round mags in the 9sc.

__________________
NRA Certified Instructor