A little variety?
Get a handgun that you can keep concealed, carry all day, one that allows you to hit what you want, as fast as you need, under any conditions, and one which has a caliber and capacity you can live with. Every person is unique. Only you can make that decision for yourself.
+1 on the above.
As you can see, many folks recommend not rotating guns. In principle, I agree with this. But myself, I like a little variety, and with the change of the seasons, clothing changes, too.
I would offer that:
1. You'll probably buy more than one.
2. You'll want a little variety.
A good balance between variety and monotonous uniformity: try to carry guns that will operate in a similar fashion. For example: a Glock or XD or M&P are "draw-and-shoot-with-no-external-safety-manipulation-type guns. Well, revolvers are the same, really. (Assumption: the Glock, XD, or M&P are carried with one in the chamber).
If you opt for a gun with an external (thumb) safety (e.g. the new XDs, the M&Ps and the zillion 1911 variants), try to stick to guns that will always provide you with a uniform set of actions to follow. In the case of the 1911-thumb-safety variety: Draw, present, thumb-sweeps-safety, on target, fire (I think I got the order right; the "thumb-sweeps-safety" part is where the muscle-memory is quite important.).
I keep 2 classes of pistols in the carry quiver: those with no thumb safety (e.g. Glock, XD, M&P (there are many others)) and 1911-style pistols with thumb safeties.
I try to balance my practice between these 2 types.
Good luck and enjoy.
