Tires make all the difference, go with a proper Michelin or Continental in my opinion. I am unsure about the V50 but I know the S60 awd should be the same haldex as what is in the mid 2000's cross country and these awd systems lock the front and rear axles together while in reverse. The car should be an absolute beast in the snow when in reverse as a result. I do also believe the rear differentials are limited slip - something which has carried over through the years from the old RWD days.

Again I am not a factory engineer but this is what I've ready in many other forums. In contrast I had a 98 XC70 and tried many times to get it stuck during snow conditions (mounted with Bridgestone Blizzaks) and was not successful....I am talking massive hills in the central MA area with feet of snow, went like a tank....I reckon the S60 and V50 (if awd) should be the same if not better.

Regards
Steve