What are speed ovens (combo microwave / oven) good or not good at?
Microwaves are fine for veggies and for reheating most leftovers.

They are notoriously bad at anything having to do with bread, or anything crunchy. Nothing will make a nice crispy coating go soggy faster than a microwave.

Some people like them for rice, I do not. I think they ruin rice.

You can quickly achieve an edible potato, but it won't have that fluffy interior or crispy skin of baked. By cooking a potato until almost done in the microwave, and then finishing it in the oven, you can get (most of) the best of both worlds. It won't be quite as good as a fully baked potato, but it'll be pretty close. I would think a combo oven would be a good choice there.