After getting a Safariland 6378 ALS holster for my M&P45 (w/thumb safety), I picked up another for an M&P9. Excellent holster, great locking system - much better thought out and implemented than the SERPA design. It takes some practice, but will give you a safer release/draw and position your hand fully up against the beavertail for a good grip. I think this is one of the best designs for an outside holster with retention.
This model (6378-219-411) fits a full-size M&P9/40.
Pros: Safariland quality and locking system
This review was written in the old system and had content requirements that are different than reviews written today.