Many of the +P .45 loads mimic or surpass the 10mm. With the XTP bullet in question I think evenhill is correct. Those bullets as loaded by Hornady, especially the +P loads, typically waste effect on people by blowing all the way through with a lot of velocity retained, tests that I have seen indicate 18"-20" or more of penetration.
Our issued +P 124gr Gold Dots typically go 15" in gel, and also typically exit in almost all of the OISs that we have had.
On people I think the effect is wasted, but Doc Roberts notes the FBI testing that the .45 was in fact better at breaking large bones.
For me, around my AO, the 9mm will do anything I need it to do for duty and off-duty use. If I lived somewhere that had big bears I'd re-think things.
I feel a strong advantage of the 9mm is cost. I can shoot quite a bit more for the same price with 9mm.
As someone with arthritis I also appreciate that the service sized 9mm gives less wear-and-tear to the shooter.
While many people profess to shoot the .40 or .45 just as well as the 9mm, I note that this is most often with a two hand hold on a flat range, on a warm spring day with a bright blue sky.
One hand shooting, around a barricade/shield/car door/injured/from the ground/in the dark with a flashlight in the other hand/carrying a baby/dragging a wounded buddy, not so much.