I shoot my daily carry gun in IDPA matches, out of my daily carry rig. I don't wear the 'shoot me first' vest, instead opting for the normal untucked shirt I use every day. The only difference between my carry rig and my match rig is the ammo (ball vs. JHP).
For me, IDPA isn't about winning the match, it's about testing my performance against myself. I want to verify whether or not my carry choices are valid and adequate. Training helps with that, but the IDPA folks come up with some weird situations that I wouldn't have thought of myself.
And yeah, the Langdon-tweaked 92 is a thing of beauty. Mine still runs like a scalded-ass ape.