Promag has come out with a 32rd 9mm magazine for the S&W M&P9. The steel bodied magazine retails for around $40. In the picture below you can see how much taller the Promag magazine is compared to the Glock factory 32 rd magazine. I was able to squeeze 37 rds into the Promag hicap.
I test fired the mag with just 32 rds and it shot every round and locked the slide on the last round. However that was only one test. But so far so good. I would have liked the magazine to continue the striations and round indicators along the entire length of the magazine, but that would have probably increased the manufacturing costs and raise the cost of the magazine.