MM... just don't talk please. I asked nicely.

Buggies are much more stable all around. In the air or on the ground buggies are extremly stable with a low center of gravity. The narrow tires actually give them more grip on dirt because they dig into the surface instead of those wide MT tires floating ontop of the dirt like pontoons. Buggies are all around much better handling.

The low end torque thing that MM brought up all depends on your engine, pipe, and gearing. That has nothing at all to do with it being an MT or a buggy.

For jumping.... hight and distance relys fully on the jump and your suspension setup. They can both jump just as high or as far as either... only the buggy will always be more stable.

Edit: It also depends on the terrain. MTs are more stable in rougher terrain as long as you have the suspension setup... the high ground clearance and the very long travel make them soak up the huge bumps. The buggy (again depending on suspension setup) will bottom out a lot more and get thrown off by very rough terrain. Very rough meaning like a construction site.