Mount: low control vs high control

In my mind mount is a more nuanced position than people give it credit for. I feel like most people just kind of sit over someone expecting that to be all that's necessary to hold them down. We talked about 2 types of mount control in class 4/25. In those two types of control we broke the low control into 2 more categories, grapevine and BJ Penn mount. In both instances we are nullifying our partners legs with our legs, attaching our hips to their hips, and pressuring down. Although this limits our attacking options from a grappling standpoint almost exclusively to chokes, it does provide us with the ability to settle our adversary and maintain control slightly better than a mid or high mount. 
Mid and high mount provide more attacking opportunities, but can also be a bit more difficult to control. The transition from low to high mount is best done in incremental stages moving one side and then the other side little by little until you've achieved your desired position. When choosing a mount position to work from, look at what you are trying to achieve, what your attack strengths are, and which control style suits your game best.