There are strategies for minimizing down time, like doing non-LL rides between LL rides. One thing that is for sure - it is NOT like MaxPass where you could go from e-ticket to e-ticket ride all day. We did find we went from attraction to attraction with very little backtracking, with our only downtime being time we purposely chose to do shopping or go back to our rental to rest and swim. Stacking during the afternoon for evening rides also worked well for us to avoid downtime between rides, especially since return times for several rides were still quite fast for many rides (not e-ticket).
In a lot of ways, G+ worked better for my family because I wasn't dragging them around as much like I did with MP, and we avoided a lot of back tracking. Things lined up well for us though, and I know it doesn't always work that way with return times.