A couple of points from a MK authorized service tech. Hard wiring any of MK's trolling motors without a means to disconnect power is a no-no. If we see that in the field and you blow a control board, MK replaces it once and after that, if you dont correct it, it is on you. Leaving it connected even if you are not charging and the motor is off, you still have voltage going into the board, and if that is constant it will result in a premature board failure.
Yes, there is a Gen 2 Ulterra. The Gen 1's had some issues, mainly with the trim housings seal design allowing water in, which would destroy the trim motor and lock up the entire unit. They redesigned the seal and top of the trim housing and it generally seemed to solve the issue. MK also has replaced Gen 1 trim units even if the TM is out of warranty (if you are the original owner). The other main issue I have seen is the worm gear tilt motor. The housing on this is cast aluminum and I saw a lot of them break where the base attaches to the frame via a SS pin. They have now redesigned the casting to beef it up and it has been a running change they made. Only other issues we typically see are sensor faults, which they redesigned one of the sensors, but most of this happens due to things sticking because of corrosion.
My opinion is the Ulterra is good, and it has gotten much better with the design changes, but it is still just too complicated. There are 5 different electrical/mechanical systems on them-propulsion, steering, trim, tilt, and ipilot/gps. Any one of the 5 can cause it to stop working effectively and when it does, manually getting it up to get it home is difficult if you dont know the tricks to do it. Unless the auto deploy and trim functions are a necessity, the Terrova units have the same key features-ipilot, electric steering, spot lock, and are simpler and thus more reliable. Repairs on Ulterras vs Terrovas I would say are in the 4-1 range in how often they occur. Many Ulterra repairs are simple and only require cleaning/lubrication, or a reset procedure, but they are annoying for a customer especially if you dont have a quick release to remove the motor from the boat.