My buddy just picked up an S&W M&P 40 subcompact, I got to handle it today. It seemed like a nice firearm. I did not get the chance to shoot it, but it felt nice in the hand, not quite too small to grip it firmly, but easily concealed. It didn't seem like it would bite the thumb web with the slide like a similar Glock could.
That would be one to at least handle when you head to Vance's. The ultimate decision is, of course, what works for you the best.
Good Shooting,
Mitch