TC is more comfortable if you like the soft cushier kind of ride. The Mark is more feel the road comfortable. Both are great for front passengers the TC is much better for rear passengers (duh). Repair wise the TC was easier to work on, more room and less complicated it seemed. Electronics failed a lot on my TC - went through 1/2 doz radios, all 4 window gears at least 2 times, power antenna, seat motor and the stupid little trunk up/down motor (Lincoln replaced that one 3 times - all under warranty). Marks have their issues - poor head lamps, heater controls, door ajar warnings bad upper control arms but nothing so bad that this forum cant help with!
Overall - TC is more of a move the passengers surrounded by luxury kinda ride
Marks VIIIs are move the passengers as fast as you can - in luxury kinda ride.
Just my thoughts...