Seriously, I can't think of any "cons" to a 3913. It is one of the most proven, robust, ergonomic, and best shooting pistols of all times. It is also easily concealable for CCW. Right now I'm wearing a 4014 which is a .40 S&W sister to the 3913.
One thing that gets lost in all of the talk about "pocket nines" is ergonomics. The 3913, in my opinion, is at the optimum, sweet spot and balance of "conceal-ability" and "shoot-ability"
By the way, the 3913 is compact alloy framed "3rd generation" S&W pistol, has a stainless slide, single stack magazines, and a bead-blasted matte stainless finish. They have a compact frame, barrel and grip.
Another gun in this family to consider is the 3914 if you are doing web searches or looking in the LGS's. Same gun with a blackened finish.
Not to muddy the water, but there is a "LadySmith" version which is engraved as such, a 3913, and a 3913 NL. All are basically the same gun but with slightly different shapes and styling. Holsters for one may not work with another.
Then there's the 4013 and 4104. Same basic guns in .40 S&W; stainless/alloy and blackened respectively. The thing to look for here is that some 4013's, particularly the 4013 TSW (Tactical Service Weapon) versions are double stack compact models. Some have rails, some do not.
Finally, the 6906 is a compact 9 mm similar to the 3913 but with double stack mags and correspondingly wider grip.
If you get the chance, definitely buy, and carry, a 3913!