I come from where you are coming from. For years the only plastic pistol I owned was a KelTec .380 some time ago and more recently a Ruger LCP. I've always preferred and only owned J- and K-frame revolvers as well as a couple of S+W "3rd Gen autos" and 1911's and a BHP. I've always wanted to like Glocks because of their well-deserved reputation for reliability, simplicity, ruggedness, etc. My only problem was I just didn't LIKE Glocks. I had been looking at the M&P line for a while but never really took the plunge. I even happened on a really good deal on a full-size 9mm and turned it down. I was always kind of interested in the M&P9c, though, and finally happened on a deal I couldn't pass up on one, "used, but barely fired". The gun shop owner told me someone ran one box of range ammo through it, decided they didn't like it and traded it right back in on something else. Not hard to believe as this was in early Feb 2012 and the fired case envelope is dated late-November 2011.
Anyway, even though I was looking forward to getting it, I immediately liked the M&P9c way more than I ever thought I would. It has proven itself to be 100% reliable so far, is easy to shoot accurately and I love the way it looks and feels. I just bought a "Shield" Friday and ran an initial 200 trouble free rounds through it yesterday. It carries more easily than the 9c being noticeably slimmer, shorter and lighter, but so far has proven itself to be just as accurate and reliable as well as handsome and feels good in the hand. No, it's not a true pocket pistol, I wasn't looking for one. (Like many guns, it COULD be carried in the pocket for a brief run to the store or what-have-you, but not what I call a true pocket pistol.) Like my other favorite S+W models, the 3913 and 3953, I feel it's a great gun because it is small, thin and light enough to be a great carry gun while being "substantial enough" to be fun to shoot many rounds through in a single range session.
Many on this forum and others have lamented the discontinuation of the 3913 (as well as other fine 3rd gens). It's extremely doubtful for many reasons (mostly financial) that you'll ever see them produced again, but maybe S+W really has been listening and is offering us the next best thing. My 3913, BHP and 1911 aren't leaving me anytime soon, but the Shield isn't, either, and in the immediate future will see most of my holster and range time.