9mm is a great round. Much of the "go .45" sentiment originates with military types, who are/have been stuck with ball ammo. Hollow points change everything. 9mm is my first choice, as long as modern defensive loads are available. If I were stuck with FMJ, I'd carry a .45.
Currently Own: Beretta PX4 9mm, Glock 23 (Gen 4), Glock 19 (Gen 4) x2