Which rides have them? Is it really only Mission Space, Test Track, and Expedition Everest? How much shorter are they? We did that at Universal on a few rides and it saved us a ton of time on the day we didn't have front of the line passes. We even rode together on the Mummy once in the single rider line. The rest of the times we were usually within sight of each other during the ride (Spiderman, Men In Black, etc.). It's no big deal and saves time. Could help with our trip planning at Disney if I learn more about it...