How is the Ruger P90 for a concealed carry. Been Carrying M1991A1?

I am a big guy, but my M1991A1 Colt is worth too much to keep carrying. Looking to buy another .45 simply because I have 5000 rounds of .45 ACP and never cared for the smalller calibers. Least I would shoot is .45 or .357 mag. I like to know the subject is going down hard if I have to "pull" my concealed weapon.