I agree w JonM, 45 is the way to go. I love everything about it except the price of ammo. I went w the XDM 9 w 4.5" and the muzzle flip is similar to 45, OK accuracy, one mag mysteriouly holds up at 14 but once loaded, it has never failed to fire all 19 +1 rds.
( I've been using 115 gr. loads w 3.5-4" @ 25 yds which acceptable but not target worthy. When I called the company, they said 3.5 was fine, and I debated eating the S&H cost. A tech advised me to try heavier loads, 124 to 147 gr before I gave up hope. I didn't bother to tell him I already had a case of 115 gr. fodder)