Just did this Saturday. We arrived at security at 7:40 and were into DCA by 7:45AM as they let folks in before the 8AM opening. Folks headed to RSR standby were held at a rope. We were set on getting FPs and I could not see where the standby rope was but I am sure it was before you get into CarsLand. I could see the rope over by the entrance to Condor Flats and there were folks at that rope too.
I do not have a feel for how many folks chose direct to RSR vs. FP, but there were a ton of people going for FP. At 7:45 we were in a FP line that snaked up Hollywood Blvd and we were almost to the Off the Page store in the Disney Animation building. The line grew back to the Hyperion theater somewhere - I could not see the end at 8AM when the line started to move. We got FPs at 8:19AM. Return window was 11:15AM-12:15PM.