I'm on my 4th Volvo and my 3rd wagon.
The first was a 95 sedan that was fine but couldn't haul much stuff. At the time the ex didn't want a wagon because she didn't want to look like a soccer mom. The car was fine, a little uninspiring, and I don't remember any major repairs to it.
The next was a 740 wagon that got a 5.0 V8 engine and transmission transplant. Repairs are hard to judge on that car since it was always being worked on. But a hell of a lot of fun though.
I replace that with a 98 v70r, my favorite. My middle daughter was born in it so it has even more importance to me, the ex kept it and it still keeps going with over 150k on it now.
When I moved up to Boston 4 years ago I needed a car that handled snow better than I do, since I'm a wagon whore, I ended up getting a 07 XC70. I bought it with around 20k on it and have over 110k on it now. I've been through a set of wheel bearing all around, I'm on my 2nd set of tires. Apart from regular maintenance it hasn't required anything else. Its been all over the US, carries kayaks, bikes, people and all their crap. Its comfortable, has a stereo good enough for me. I've been very happy with it.
I do look in at volvo XC forums once in while to see whats happening. Early models seem to have had transmission issues, but the 07's don't seem to be an issue there.
I'd get another one if needed. Of course if I wasn't living in this place, meaning somewhere warmer and less crowded, Id might be looking around. But only for the change not to fix a problem.
Good luck with your search.