I've had mine for a month now, I like it and wouldn't change back to pressure washer method.
A moderately dirty sedan with an overcast day, and several dead/smashed bugs takes me about 15-20 mins wash, thats just 1 person. Now, I have had a muddy, big dually truck and it was a pain in the rear because there was a lot of mud...everywhere and it took 2 of us about 1 1/2 hrs to wash the outside, with only 1 gun going.....it was horrible.
I'm trying to figure out a system, and once I figure that out...I think things will go smoother.