The shaft on the MG is more fragile than Minn Kota and not nearly as good in weeds IMO.
Eric, these have been my thoughts on the MG TMs for many years, which is why I have used Minn Kota motors for so long. They just plain work for me.
Regarding the 36 volt setup, are you using your cranking battery as part of the 3-battery 36 volt setup, or do you have room for 3 batteries dedicated to the TM only, and an additional battery for cranking?