I own a SD40 (along with a Glock 19 and 23). I really like it and I posted a thread "Smith & Wesson SD40 Rocks" you could take a look at, but all in all, it feels really good in the hand, I'm getting three inch groups offhand at 25 yards with the Winchester 165 grain "white box" ammo, it never fails to feed, fire or function, and I think it looks really good, kind of like a M&P slide over a Sigma receiver, only (I think) better. I like the four inch barrel and am now looking at getting a M&P compact with the four inch barrel. If somebody would come out with a conversion barrel in .357 Sig, or from .40 to 9mm, that would make it even better. (Stormlake, KKM are you there?)