Setting up the camera goes faster if you don't break it down as far when your done with an exposure. I've meet people who will break a camera completely done after an exposure and put it back in a carring case just to walk sixty feet. That wastes a lot of time.
I use a majestic head and take it off the tripod attached to either my 8x10 or my 8x20 (whichever I'm using at that moment) and place the whole thing in the back of my Jeep. I carry the setup into my house that same way and set it up on my camera stand. I think I only fully break down the camera about three or four times a year when I need to pack it into a tighter space in the car.
Also 10-20 holders sounds nice, and makes great press,but more often then not most ULF shooters are working with less. I have four that I fully trust, two that are fine indoors. Its costs about the same to buy a Harrison changing tent as it does to buy one new 8x20 holder.