It depends each one's favorite.

If it is I5, I think turbo is necessary. 6cyls, I do not think so, unless you like to hit the paddle to the floor. S80 is not a sporty car.

AWD helps some in snow and icy days, but still can not run over heavy snow, the ground clearance is too low. A set of good tire should be OK for regular snows, as long as you drive carefully. If you do not have a SUV, an AWD may help you in some days.

My S80 was stuck on highway a couple of times due to a heavy snow and "old" tires. But after I changed to a set of good tires, feels better. But I will use SUV when there is a heave snow.