I used to use a quad bike and a trailer. It was loads quicker! Still had to manually poo pick though, but saved time by driving the quad and it excellent fun!
One of my clients hires out Muck Trucks and to be honest they are more trouble than they are worth, they are forever breaking down, you would be better off with a qaud bike and trailer I think
we had a 3 wheeled muck truck for doing th stables on top yard, or digging out deep litters i loved it i was one of the few that drove it & the only 1 to get it into 3rd gear !! i didnt use in field but friend did though not as fast