I own both an 850 and a V70, drive each regularly, so I can give you some comparisons:

1. Shape: 850 is more "boxy" than the V70. The V70 nose slopes down.

2. Interior: mostly the same, but the V70 is just a bit more refined--"softer".

3. Chassis: this is a tough call, b/c my 850 is a '94 turbowagon, and my V70 is a '98 R AWD, so the suspension is COMPLETELY different on them. But, in general, the V70 tends to have a better ride from my perspective. Not softer, just more predictable, and definitely the chassis was stiffened btw. the two years.

One thing I'll say is that the '94, with 20 less HP, is faster off the line and in general than the V70R AWD.

AFAIK, the 850s didn't have ABS problems, but the V70s have. My 850 *did* have an evaporator problem, cured under warranty.

If you get an 850, or anything that's up there in miles, look closely at the transmission. I just had to fork over $3k to replace the transmission in my '94 at 118kmi last year, despite the fact that I'd changed the transmission fluid more often than volvo recommends.

Good luck!