Kind of boils down to what an individual wants and how much they perceive it is worth. Personally I prefer the 1980 4/6 with the individual heads but still the 4 plug motor. it had the vari-ride suspension, the 2 up seat, wider skis, and cooling system of the 82 sled but the motor with the Mikuni carbs is easier to find parts for and the carbs worked better for me.
I like the old school look of the motors compared to the single head across both cylinders. Even with the uneven cooling this caused, it is a 'looks thing' not a functional thing.
I also enjoy the restoration part, tracking down the part that is missing, correcting others mistakes, etc combined with the first time it comes to life and the first time down the trail! nothing can compare.
But that is just me. to each his own