I bought my car with 105,000 miles on it as the fourth owner. I had it for a year. It was awesome as a college student to be able to haul around my friends and my stuff. However, previous owners had not cared for the car properly and I ended up with a blown piston ring after a year of ownership. That pretty much totaled the car ($3k of repairs for a $3k car) unfortunately. However, I bought a used 2002 XC70 because I loved my 850 so much. It was taken on several car trips (camping, skiing and paintball) and performed well in all areas. I wish I could have bought another. Be aware when buying used- if the person before you hasn't done the maintenance, the car will fail.
Sunroof, 3rd seat, individual reading lights over the rear seats (perfect for friends to read or do homework on long car trips), window controls in middle console, dual climate control.
Cupholders! This is the primary complaint from 850 owners- there is only one cupholder that is actually useful and they are placed in such a way as to seriously cause harm to the electronic window controls.