A-R wrote:I occasionally carry my full-size M&P45 in a Comp Tac MTAC. No problems with it except at 4.5-inch barrel it's just a hair too long for maximum comfort (my M&P9 with 4.25-inch barrel carries more comfortably - go figure). The extra thickness of the 45 is almost unnoticeable compared to the 9mm M&P or any of my Glocks.
M&P45C should be no problem - about same size as the Glock 23 I carried as primary for more than a decade - and that was before all these fancy new "hybrid" IWB holsters all you young whipper snappers use today
I conceal my full-sized M&P45 in an OWB holster also, as well as with a shoulder holster. The "difficulty" of concealing full sized semi-autos is overrated.