The "Commander" style pistol concept originated by Colt appeals to a lot of people. To me, a full size frame and shorter slide balances better and there isn't as much weight hanging out front but rather the weight sits on top of your hands vs in front of them. I'm not sure I'm explaining that clearly. The Glock 19X balances better than a regular 19 for me, and I prefer my Colt Commander Rail Gun to my Government Rail Gun for the same reasons.
ETA - I just picked up an IOP M&P 2.0 Compact 4" on Wednesday along with a blue label Glock 19.5. I really like them both though I haven't had an opportunity to shoot either yet. When I can put eyes on a 3.6" M&P I might not be able to resist the urge to bring it home.