I mostly shoot USPSA. This year I have squeezed in a few matches at local club puts on an IDPA style defensive pistol shoot twice a month.  Yesterday for the last shoot of the season they did a night shoot.  Wow!  What a good time.  Being IDPA style they allow headlamps, weapon mounted lights and lasers along with flashlights.  For grins I shot my 9mm M&P Shield in CCP.  (I only have 3 mags so BUG is out)  I placed 1st in CCP and 17th overall out of 43 shooters.  

If you ever have a chance to do a night shoot do it!  

The IDPA club I shoot at has a night shoot coming up in a couple weeks. Unfortunately they are not allowing lights mounted on handguns, only handheld. No headbands either. They are allowing lights mounted to PCC's though, so guess what class im shooting...
Do expect it to be fun though.

One of the most aggravating things about IDPA to me is the gear rules.  My real life EDC gear: light-equipped G19 and 45° IWB mag carrier (carried at 11:00) are not allowed in IDPA, but are allowed in USPSA.  

Yeah I never understood some of the rules they have considering idpa is supposed to be based on "real life".