My opinion is go with the 9mm and honestly to *me* it is a no-brainer. First off 9mm is just flat out cheaper. You will shoot more with 9mm than any other non 22LR load. This means you are allowing yourself more time to be a better shot.
Second 9mm with modern good defensive ammunition is absolutely fine as a defensive round. There are tons of threads and links and all the information you could ever want to compare the effects of 9mm vs .45. My opinion, formed by reading the information available, is that they are almost the same. (Assuming you use modern quality defensive ammunition.)
Third, mag capacity. In the M&Ps we are talking 10 vs 17 rounds. If you carry a spare mag that's 34 vs 20 rounds. That is a *huge* monumental difference. That difference in round count (IMO) more than makes up for any possible difference in the bullets effectiveness.
So really for me the comparison comes down to this. The *only* rounds that count are rounds that you are able to put on target.
Cheaper, 70% more rounds, easier to shoot...all these make 9mm the only option. I honestly don't see any place at all for .45 in a defensive handgun. (Hell if they were the same price I would still pick 9mm!)
Second 9mm with modern good defensive ammunition is absolutely fine as a defensive round. There are tons of threads and links and all the information you could ever want to compare the effects of 9mm vs .45. My opinion, formed by reading the information available, is that they are almost the same. (Assuming you use modern quality defensive ammunition.)
Third, mag capacity. In the M&Ps we are talking 10 vs 17 rounds. If you carry a spare mag that's 34 vs 20 rounds. That is a *huge* monumental difference. That difference in round count (IMO) more than makes up for any possible difference in the bullets effectiveness.
So really for me the comparison comes down to this. The *only* rounds that count are rounds that you are able to put on target.
Cheaper, 70% more rounds, easier to shoot...all these make 9mm the only option. I honestly don't see any place at all for .45 in a defensive handgun. (Hell if they were the same price I would still pick 9mm!)