FWIW, about 10% of the students who show up to one of my classes make the sub-7 time once out of four tries over the course of two days. And that's from a pool of shooters dedicated enough to spend $500 plus travel, ammo, etc. to take an intermediate-level technical pistol skill-building class.
A higher percentage of shooters make Basic (greater than 10 seconds) than make Advanced (less than seven). And again, that's best out of four tries.