Bought for reasons of safety and value at end of model run (before the S80 redesign for 2007). Wife had bought our first Volvo (2004 XC70) and was pleased with Volvo ownership experience (good ride, solid, secure feel, and attentive dealer service.) Same engine (5 cyl turbo) as XC70, but quicker and better handling (17" wheels).
Understated, but refined, interior. Comfortable seats, good factory audio system. Secure, responsive handling. Safety features a real plus (whiplash protection, side impact protection, plus higher tensile steel in roof & pillars.)
Quirky radio controls (also a problem on XC70) have apparently been addressed in newer models. Can't open trunk with key in ignition. Drink holders awkward. Actual mileage averages 19 locally, 23 on highway, but could be better (regular gas).