So now what happens to the M&P9c and M&P40c? Isn't this similar to what S&W did with the Sigma -vs- SD line? I understand the Shield is slightly smaller and lighter but am I the only one confused by this new line-up?

Given the dimensions of the M&P 40 Shield are similar to the 9 Shield, why do I carry the Shield -vs- 40c? Because I can't handle the extra 1.3" length, .3" width/height or an additional 7 oz? I understand S&W is going after a very popular CCW market right now but does this mean that the 9c & 40c is going to slowly die off? What am i missing here?

Shield: (edited mag capacity, oal, oah, oaw, weight)
Caliber: 9mm
Capacity: 7+1, 8+1 (magazine with grip extension) M&P9c 10+1 (CA) 12+1
Operation: Trigger cocking DAO; lock breech; "Browning - type" recoil lug; passive striker block; no magazine disconnect
Barrel: 3.1", polygonal rifling; 1 - 10 right-hand twist
Length O/A: 6.1" M&P9c 6.7" (+.6")
Height: 4.6" M&P9c 4.3" (-.3")
Slide Width: .95" M&P9c 1.2" (+.25")
Weight: Pistol 19 ounces, Magazine 1.9 ounces M&P9c 21.7 oz, Mag 9.1 oz
Grips: Textured polymer
Sights: Drift adjustable, white bar-dot combat sights
Finish: Black polymer frame, matte stainless steel slide
Magazines: 1 each: 7 rd flush floorplate & 8 rd extended grip