The glock 19 blows the M&P out of the water. It is more reliable and shoots better than the M&P. The Smith's are bragging about torture tests of 50 to 60 thousand rounds while the glocks are going several hundred thousand round torture tests. That is just a no brainer to me. I own several glocks and I am biased to them only because they are the best all around pistols out there. You cannot and will not go wrong with a glock purchase. I own two Gen3 Glock 19's and they are like my children. But they never act up.
Shooting-wise, how do you like the M&P 9c versus the full size M&P9?
The 9c shoots amazingly well! So far, it is as accurate as my FS (4.25"), except it seems quicker to target, probably because the shorter sight radius (and probably also because mine has the big yellow glow sights). The biggest difference is slightly more recoil on the 9c, however, nowhere near the recoil of other compacts like the XD9SC.
Bottom line, my M&P9C is a joy to shoot, and as accurate as all my favorite full size pistols (PPQ, 92FS, PX4, P95, etc.) . . .