I've ran the USPSA program at a local club for about 8 years now, and
shoot matches several times a month at local clubs. Have been to area
and National matches too.
Shooting about once an hour is pretty normal. You want the time to go
a little faster? Get off your butt and tape targets. Take a turn as
scorekeeper. Help pick up brass. Take the RO course and take your
turn running shooters. It's a volunteer sport------do your part.
Probably the fastest "action" type competition is GSSF. Steel Challenge
and IDPA are about like USPSA as far trigger time.
I've tried the scramble format a few times, and know of at least one
club that uses it all the time. It can be a bit faster, but not by much.