1 benefit to having HI's unconstitutional gun laws is that magazine cap helps this issue.
With only allowing 10rd mags, 1911 45ACP have reliable 10 rd mags. And anything more than that is not common to use. Where I'm going is if someone buys a G19, they cannot have a 15rd mag, it has to be 10 rds. Same would go if someone buys a double stack 45 like a HK. Max capacity would be 12rds, but due to our law, must be lowered to 10rds.
If I were to get a 45 right now, a 9mm would still be my choice because I have the most time spent training with it. Then once I get proficient with 45, my choice may change. This is 1 big reason why I have not bought another gun in 5 years. I want to get decent enough with what I got before I get another caliber. I'm still no expert, but good enough to advance to another caliber IMO.
Many things to factor in besides the mag cap. Recoil control and accuracy would be my top 2.