While I will never steer anyone away from a Beretta, I will say to try them both. I've been a Beretta shooter since 1998 and I love the platform. That said, there are better and there are those that will fit you better.

On an aside, a better comparison might be the M&P 9 vs the Beretta 92A1. The 92A1 is the newest incarnation of the 90 series, it has a full Picatinny Rail, recoil buffer, and removable front and rear sights. It was a toss up between that and the M&P I ordered.