The Roper has a very low turn speed, but a high chassis rotation speed. While this is typical for Tank-style vehicles, the Agrav feature of auto-aligning the body to the chassis makes piloting the Roper a disorientating experience.
This hulking monstrosity is what happens with Corvid access to farm equipment and too much gasoline to huff. Old tractors, car doors, motorcycles maybe? Weld'em up with as many agrav power plants as needed until the thing is airborne. Gunners hang on for dear life to the outside, blasting away with abandon. I suspect these things still flip over and maim their crew just as readily as the old tractor it's built from did.