I've owned three motoguides and 3 minnkotas. Fewer problems with the Minns. The motorguide service I got was awful. At one time our local service shop in Ohio would not service warranty because Moto was behind on payment. That was mid 90's.
On the other hand, I've had great service, although rarely needed, for my Minnk's. Moto makes a great bracket, but if you use a bounce buster....that is a wash between the two. I've found the minn to be better in weeds as others stated. I've also found that huge prop on the minn to be better holding without cavitation on open water.
I know Moto has the new digital system, but right now, if I was buying new, I'd get the MinnK without a second thought.