We walked on to 7DMT last week just after 11 pm, and then PP after that. We didn't wait for more than a couple of ride vehicles at either ride. Posted time was an hour for 7DMT, and I think around 40 minutes for PP. We did notice that there was a bit of a line at both rides when we came off, but the backup point seemed to be the band-scanning to get into the ride queue, not the ride capacity itself.
One note: Splash does not do extended hours. We had a G+ earlier in the day, but it went down and stayed down for several hours. It finally came back up sometime after 10 pm, but was showing a long-ish wait, so we decided to use our G+ for BTMR instead and come back to ride Splash just before leaving, since we didn't really want to walk around wet at that hour. That was a mistake; when we came back around 11:30, the ride was still running, but the line was closed. :-(
After that we left. I felt a bit like we were "wasting" the extended hours, but it had been a very long, crowded day, and we had to get up fairly early to catch our flight home. The two rides we did do would have easily cost us a couple of hours of wait time earlier in the day though, so it really wasn't a waste at all. It meant that we could concentrate on rides with relatively shorter waits earlier in the day, knock off the high-demand rides quickly after EE started, and still get a relatively decent night's sleep!