Be aware that they open and close the single rider lines at will on some of the rides. There doesn't seem to be any rhyme or reason to when they are open. At first we thought maybe standby had to be at least 60 minutes for them to be open, but that turned out not to be the case. We were there last Weds-Sun, we did single rider for Space Mountain, RSR, and Smuggler's Run. We tried to do RSR a 2nd day on last Sunday when the standby was over an hour, and were told they were not doing single rider. Every time we checked at Indiana Jones, we were told there was no single rider line. On Space Mountain last weekend we did single rider, but the guy filling the coaster, was only pulling a single rider about 1 out of every 5 times there was an empty seat. We we wondering why it was taking so long, and then as we got to where we could see the cars, we could see what he was doing. The people in front of us, were telling the people in front of them, they should just go up and stand in the row without being told when there was just one rider because they were getting irritated he wasn't filling the empty seats.
If they are open, they are definitely worth it on RSR, Space (assuming the seats are being filled) and Indiana Jones and if you don't mind being the engineer, on Smuggler's Run.