I always feel bad cause if my tanks are full it takes a good 10 minutes to get them all drained. This rarely happens. I am fortunate enough that there is a built in flusher for my black tank so I can hook up the rinse hose at the dump (when the threaded end is there) and flush the black while the grey tanks are draining. 140 gallon capacity over 3 tanks isn't a quick proposition. I generally plan for not being in a rush to get out. If we are far from home and have to keep time on our return trip we plan for FHU so we don't have to worry about a line. Mostly to be considerate of those behind us.
