+1 for MP 45 and in particular, the 45c. It's not a sub-compact, but an 8+1 with plenty of heft for a polymer. Most folks seem to like the feel a lot, at least I've never heard anyone say otherwise. I believe it is among the M&P models that can be had with a thumb safety if you like that feature, however I've never shot an M&P that was configured with one.
I personally don't care for the feel of the XDM at all, and most definitely not the XDS--shooting these for me is like wrapping my hand around a snow tire--or a bench grinder. I've only fired the little single-stack and really didn't want any part of it. The MP45c I can shoot all day long (and often do)--it's worth a look, but I suppose if you don't even have the opportunity to touch and feel various guns, the recommendation is a bit pointless. Everyone has their favorites--usually the ones they own.
Other considerations might be more important for you if it's remotely possible that a child could get hold of the gun--in other words, IF there was an oversight, a firearm with an external safety might add just a little bit of forgiveness for an error already made. I only mention this because a large number of options are available without external safeties, and in fact that's the more common option for the M&Ps AFAIK. I don't know how you can know which option you'd shoot best or even which one would be the most comfortable. I was able to handle at least a 1/2 dozen smaller 45s and shot at least 3 of them before getting hold of the M&P, which I bought then-and-there after pumping a box of ammo thru it. If you're simply not able to do that, I really wouldn't worry about it too much--you can learn to shoot whatever you decide on, and you can learn to shoot it well.
I'm NOT even remotely suggesting an external safety is a substitute for preventing situations that cause inexcusable 'accidents'. I'm suggesting some things to consider that might be far more meaningful than color and styling, for example.
Final comment: I'm not sure it's important, useful or even a great idea to have a different weapon for home defense than for carry. While you can definitely take advantage of added weight, size and capacity (they kinda all go together) when you don't have to carry the gun, these may not overcome having to deal with a different weapon that handles differently. My home defense weapon IS my carry weapon, because I generally carry while I'm awake--in the home or otherwise. When in bed, I do often have the big brother to my G29 (the G20) on my nightstand, but it pretty much an identical gun other than 'feel'. Generally, they behave the same for me.
Happy hunting!
) but it seemed to fit my hand the best. 
