If the opportunity arises that a .45 and my budget permit, I'd try a .45.
I'd rather have 10 rounds of 9mm than, say, 7 rounds of .45. When all is said and done, and ballistics are minutely disected ad infinitum, I just feel that shot placement is >90% of the equation.
Isosceles? Weaver? I practice shooting over my shoulder while running away!