The NG SF groups used to run 2 week JS in Ft McCoy WS and in Utah. Basicly they worked everybody long hours and no weekend off. I have talked to folks who went....evidently it was a smoker.
I have good friend who was on the Airborne Committee that SF had in Panama. I don't how long it was, but he said they "ran the shit out of the students".
The Air Assualt school I went to was also a compressed class it was 8 days long. It was run at Camp Gruber OK by the NG. It was a well run crs too.
Also the legandary 1st Special Service Force of WWII fame ran a compressed JS about a week long. Though not sure if they did all 5 jumps though?