GSSF, isn't really like IDPA; no work from the holster, no timed mag changes, no scenarios. But, it is in terms of accuacy; shot placement is more important than speed.
is where you can find out more.
For someone like me, that has an 80% VA disability rating, it's less painfull. I do enjoy it.
...and most likely, if you hit one of the matches in the SE (GA, FL, SC) you may run into Mas Ayoob, who does shoot GSSF w/a G30 & discuss the merits of short barrel acuracy.