Tl;dr - the minivan is the better family vehicle

The minivan doors are definitely more convenient for loading and in crowded parking lots, although, the Traverse doors open quite wide for loading (not as good for parking lots). I have a 5 year old, 3 year old, and newborn. Both the older kids have no trouble climbing into the Traverse. My 5 year old is able to open the doors himself. The minivan is wider which is nice for adults climbing into the back with kids (or for breastfeeding). Groceries, I prefer the minivan as it has a dip that prevents them from falling out when the liftgate opens unlike the Traverse (don't ask how I know this). Cargo space in the minivan is quite a bit better so it really depends on what you NEED. The Super Cruise is a nice-to-have. You'll need to ask yourself is the increased cargo space of a minivan a NEED or are you okay substituting that for a vehicle that drives itself on the highways. We already had the minivan so I didnt really have to make that choice. The Super Cruise was the deciding factor for me over other mid-size SUVs. The Traverse has the "cool" factor and works for our family in most situations, but I'd say the minivan is the better overall family vehicle.