Well, fate kind of helped me decide what to get. I went to my local Gander Mountain, not with the intention to buy yet, but to get a feel for the three. No Smith M&P .45s in stock, but I got to finger up a .40. I decided I don't like the Glock grip angle, which is why I gave my model 17 to my son. They just happened to have a used XD-45 Tactical that probably didn't have 100 rounds through it by looking at it. It was love at first sight/feel/price. It came with the XD gear including three magazines and the guy had also included a Blackhawk CQC Serpa paddle holster. I was really impressed with the grip feel and the overall balance of the gun, and I really was holding out for a 5" barrel (as in Tactical), so it made the trip with me to its new home. I can't wait to shoot it. I guess one big factor between the M&P and the XD, if you care about such things, is that the M&P only has a 10-round magazine and the XD holds 13. That should git 'er done!
Thanks for all the great advice,
Steve