In almost 200000 miles of daily driving, I have only had to perform regular maintenance, except for:
Electronic throttle (replaced at 118K)
Trunk struts (replaced at 64K)
Radio power antenna (replaced at 165K)
My Volvo dealer has said to me that the most important thing is to DO your maintenance when it's supposed to be done - it's not as important as to precisely what you do (specific brand of oil or spark plugs, for instance) as it is to so whatever is required, when it's scheduled. I have followed this advise religiously and have a quality car that has many thousands, or hundreds of thousands, of miles left in it.
Oh, and I use regular oil, changed faithfully every 5000 miles. And the car burns regular gasoline, too.
I have recently gone through a series of high mileage maintenance items, some of which are not cheap (motor mounts, for example) - but they're much less expensive than buying a new car, and they are to be expected. In the overall scheme of car ownership, the cost-per-mile has been very good - and what I spend on maintenance is money that I don't have to spend on a new car.
Maybe I just got lucky - but, then again, maybe the car has responded to being maintained properly.
Volvos are about safety and reliability - I can attest to both. The car's safety mechanisms have let me avoid several accidents - and when I was rear-ended (by another Volvo) the only damage I had was a bent bumper bracket that took a couple of hours to straighten. And the Volvo that hit me had no damage at all.
With almost 200,000 miles on the clock (I'll have close to 220,000 by next summer), I would have absolutely no hestitation about taking it on a cross country trip, or up a mountain trail, or somewhere far away from service. I drive 4000-5000 miles a month, and the car has been, and continues to be, up to the task.
With gas prices over $3 a gallon at the moment, I am most satisfied with the S70's mileage of 33 mpg highway (which is most of my driving). And that mileage gives me a cruising range of well over 500 miles between fill-ups, too. I get in the mid-20s in city driving.
My many hours driving the car (I'm its only driver) attest to the comfort of the front seats. Taller (over 6-foot) rear passengers sometimes wish there were more leg room - but some of that is because my driver's seat is quite far back.
I have used the car for several moves, and have loaded as many as 30 packed liquor cartons into the car, using all available seats, floor space and trunk space. Quite a nice load for a mid-sized car.
In short, I recommend the car to everyone that I can - I would buy it again in a second - and intend to keep it for many more miles and years to come.