Making a workbench

I am thinking of making a work bench to go in my garage.

I have been watching lots of videos on youtube about it. Most people make a sort of box frame then attach the legs and top to the frame.

Would it be ok to make one just out of four legs and a MDF top? Would this be stable enough to use as a workbench or am I better off going for a frame with the top screwed in to that.