We were at Epcot on Thanksgiving Day and couldn't get their until close to 11:00 a.m., so things were pretty jammmed up. Mission: Space showed a 70 minute standby wait and Test Track showed a 90 minute wait when we arrived. However, Test Track FastPasses were already up to around 7:00 p.m. (and were gone for the day by 11:15 a.m.), while Mission:Space FastPasses were for 2:00 p.m.
We had to leave before 7:00 p.m., so we got Mission:Space FastPasses and got in line for Test Track. The Test Track wait turned out to be only an hour.
When we came back with our Mission:Space FastPasses, I think the standby wait was still around an hour. We got right on and went back to Test Track, which was showing an hour wait, which turned out to be only 20 minutes for us.