I unload the mash by hand (it really sucks in the high heat of summer) but it doesn't take too long. A farmer comes and picks up our grain so it never sits around longer than 24 hours. That particular batch was a 1.070 IPA. I have brewed 10 bbl batches of 1.090 beer that fit nicely in my MT but at 15 bbls that was definitely the limit of our MT (actually, it was 14 bbls - I was filling both our 7 bbl fermenters at once.)
We have an agitator but it spins too fast (need to get it slowed down) so I dough in by hand with a canoe paddle.