I have a GMG DB also and went from rolling it easily in and out of my barn to a Pitts and Spitts Maverick 850. There was about a half inch drop from concrete onto crushed granite. I had to use paving stones to build a patio that is level with the barn floor because the P&S weighs around 225 lbs (I think) plus it holds 30 lbs of pellets. It's a beast and wouldn't roll in the crushed granite. It sank is a better way to put it. I never had an issue with moving the DB in or out or rolling it around, but the Maverick was too heavy for me to easily muscle around. Of course being 5' 7" and 145 pounds doesn't help any either.