My experience, applies to those known to carry with some regularity or intentional thought... 3:00 OWB and possibly a 9:00 spare mag prevail in CCW. Where it varies, it's a 4:00 OWB or maybe IWB. Lots of open front garments of all types. Fishing/photo/RR type vests aren't uncommon (mostly cops) but don't seem to last on the same person long. Lots of leather, western, or fleece/softshell vests. Otherwise, it's pull-over somethings. Some variation for weather conditions.
With less regularity or intentional planning, there's more off-body carry, some variation on the above, and whatever was on sale at the gun counter.
This is what's represented at club matches I've shot. Anyone else doing anything else was a small minority.