Personally, when I can carry, my vote is "other". In the past, my most common carry guns were my Taurus 85CH and S&W 442 (often both; the 85CH IWB and the 442 in a pocket). Recently, when I've been in VA, either my Kel Tec Pf-9 or my SIG P290RS have come with me. My Taurus PT140 Millennium Pro gets about 20% of my carry time. I'm in the market for a winter carry, something in a .40 or .45, something a little larger, but none of your options are on my list (all were at some point, but they have been dropped; it is now the SIG P250 Compact, SIG P229, SIG P239, and SIG P220 Carry, all in .40 or .45).
On your list, the only definite is that I'd drop the XD (or make it a .40, or the 4-4.5" XD or XDM instead of the XDS). I generally avoid .45ACP in a barrel shorter than 4" (they can fail to achieve enough speed for reliable hollow point expansion).
I like revolvers so the SP101 would be high on my list. I'm am a big fan of 9mm and .38spl, but not so much during the winter. Heavy, layered winter clothing can increase the chances that hollow points will fail to expand, so I prefer a larger bore this time of year. I am a fan of .40S&W (really, I see advantages and disadvantages of all of the big 3 auto calibers, so I like, and own, them all). I really like the M&P on paper, it also feels good in my hand, but I am not a big fan of its trigger. That is very subjective however, so if you like the M&P's trigger, that is probably the way I'd go.
Last edited by chaim; December 28, 2012 at 10:11 AM.