We were just at IOA and USF on 2/11 and 2/13, and never waited in line longer than 10 minutes. In fact, most of the time, there was absolutely NO WAIT. (The only time we DID wait was because the show had just started --like at T2 3-D and Poseidon's Fury). We arrived on the 11th sometime around noon or 1pm and left about 4:00 to get to Arabian Nights. We went to IOA again on the 13th at 11am to see a couple things, then hit USF by 1pm. In less than 2 hours at IOA that morning, we saw Poseidon's Fury, Eigth Voyage of Sinbad, rode the Dueling Dragons and watched the wishing fountain. We walked at a VERY leisurely pace.
At USF, we saw/went on everything except Kong and Beetlejuice and the Gruesome Makeup Show (and the Woody Woodpecker kids area). We ate lunch during our time there, too.
We would have liked to have a couple more hours at USF just to see Nickelodeon, but the park closed at 7pm.
I just gave this "report" so you'd have an idea of time. If you're going during the busy season, I'd say FOTL access is probably worth it, but if it is during low season, I wouldn't worry about it, because, like I said, we didn't get to the parks early, and had NO wait time.