We were just there last week. We did get a GOTG FP first thing, because the line was not very long compared to the standby line. We got to the gates about 7:45 for an 8am open. Hung out near Disney Jr until 7:55, then they started taking FP guests to the line. Got our fastpasses at 8:05 for 8:50-9:50am. We then rode other things until 8:50, when we pulled a RSR fastpass before riding GOTG. So getting the FP did not waste time, in my opinion. We have typically started the day heading to TSMM first, but now that it has fastpass there is no reason to do that. GOTG is my new favorite ride in California, it is so much fun!