I used an H&K USP Expert in .45 caliber in both, a local Combat Pistol, and a Defensive Pistol league. In 2006 and 2008 I took first place for the year.
2007 I switched to a 1911, only took 2nd place that year.
Shot some IPSC with the Expert, did OK.
Of course I was not shooting in open class either.
Some of those open class shooters .....whew.
Shot IDPA with a standard USP.
Didn't do too bad with that one.
I love the mag release being "in" the trigger guard.
Makes for a real quick reload.