invertedflyer
500 ft. from said obstacle
PLC-Combined. Keep in mind that the 10 week version has more medical attrites than the two 6 week version simply because there's no "break" or other chance to heal. Overall though, I'd rather do it all at once. I'd hate to have to come back for the second 6 weeks. Once you're there, it's more palatable to just get it all done at once, providing you don't get hurt.
As far as "pushing yourself to the limit" goes, I feel that I was pushed very hard at both places. It's apples and oranges to an extent due to different training objectives. AOCS tried to make an officer out of you. Marine OCS was a ten week long try-out. They "make" all the Marine officers at TBS out of the ones who made it through the "try-out".
Coming back for seniors is an experience that haunts my dreams to this day. It was just bloody aweful coming back to that swamp that is Brown Field. I agree, 10-week is the way to go. If I had to do it again (my family would have to be held hostage or something) ... then I'd go combined. They pretty much just cram everything in jrs. and srs. into that last 6 weeks, you even repeat alot of stuff. You don't have time for much, and your body takes a fierce beating. Our attrition rate was only about 35% though.