They are two very different lenses. The 100mm macro is a normal 100mm lens that happens to be able to focus down to 1:1. It's great for large bugs like butterflies, dragon flies, mantis, and for flowers, basically anything longer than say an inch. It can also be used for portraits, kids, landscape, basically anything you ouwld use a 100mm lens for.
The MPE on the other hand is just for macro. THe longest it can get is going to be an object the size of your sensor or say for simplicity, about an inch long. Then it foes in from there to the very small.
Also, the MPE is not a manual focus lens, it is a no focus lens. The only way to focus is to move either the lens or the subject toward/away from each other. There is only one point that will be in focus at a fixed distance dependent on the magnification being requested.