Have shot them in the past. Lots of fun. None of the movement/reloading sorts of things that occur in USPSA and IDPA, (nor drawing from the holster either) and is a good, quick, 3-stage competition that rewards accuracy at speed.
Courses of fire are set so you know exactly what you will need to have for skills, and requires only a gun, magazines, and ammunition. (No extra equipment needed, other than of course eye/ear pro.)
The RYG matches are where I suggest most people start for shooting competitions, simply because it is all about accuracy at speed, and you don't have to worry about having lots of equipment, nor skills like draws, reloads, movement, and stage breakdown. Just: can you shoot quickly and accurately.
Fun stuff!