I'm a big proponent of firepower myself, but when it comes to handguns, its a little different. Yes, I have a G3 clone and a 10 bore pump shotgun ready to go, but my handgun won't ever go above 44 Magnum medium loads, and even then, I stick to 357 Magnum and 45 ACP. There comes a point with handguns where too much power finally leads to such a loss of follow up, the extra per damage/penetration potential is not worth the blast and recoil. 45 Colt is a big boy without any +p, and is a limit into itself for self defense consideration, really.
Like has been said already, in reality, 45 Colt standard has enough heat to be good with almost anything, there are a few hollow point choices available, and even the flatnose and wadcutter bullets will do well with the kind of weight, diameter, and power you are considering. Extra power might not make the gains in terminal performance you hope for, and even then, the eternal question if they are worth the muzzle flip remains. If you reach a point in your training where you can handle bigger, badder rounds quickly and comfortably, you have reached a place where you don't need to be seeking advice.
I'm not entirely sure if the DPX really is the best choice even then, considering its design. Are six razor sharp points in a petal better than a big ugly dull mushroom? Not if they are the same diameter of expansion. We prefer to crush than cut, and advertising as "razor sharp" is not a good thing at all. There are some other proven designs out there, and many in standard pressures, which are probably going to be better in the first place, and probably the same power and recoil as what you train with.
