Some sources researched by TheCarConnection.com raise quality and comfort issues that lower the rating of the 2009 Cadillac STS-V, but most reviews have positive things to say.
Observations from several reviewers conflicted regarding the abundance—or lack—of space in the STS-V. "The STS-V's long wheelbase means there's generous legroom in the front and back,” says Edmunds. Consumer Guide, while generally agreeing, is slightly less generous referring to the rear seat: "The seat itself is well contoured and offers good back support, though a longer seat bottom would enhance long-distance comfort. Headroom is just adequate." Forbes Autos also gripes that the rear seat is "surprisingly confined for a midsize luxury sedan." Consumer Guide finds some redemption in the fact that the "standard power tilt and telescopic steering wheel helps dial in a comfortable driving stance." Edmunds says ultimately, the STS-V will “have some appeal to those who need the maximum amount of space available in a high-performance luxury sedan.”
Consumer Guide lists 13.8 cubic feet of cargo room for the Cadillac 2009 STS-V and likes the rear storage area's design and space utilization, but harps, "Trunk space is unexceptional for STS's exterior size," going on to say, "Small-item storage is limited to a smallish center console and less-than-generous glove box." Edmunds says, "The trunk is also smaller than what one might expect for this class of car."
Car and Driver likes the interior improvements carried over to the 2009 Cadillac STS-V from base STS models, but still laments: "Unfortunately, nobody thought to soften the edge of the center console, which still bruised our knees after just a few hours of driving." Forbes Autos, on the other hand, is more forgiving: "The interior uses high-quality materials and the controls are well laid out." Edmunds reports, “There are some demerits, though, mostly having to do with some low-grade plastic trim pieces that put the STS at a disadvantage against the top European and Japanese luxury sedans.” In general, the Cadillac STS-V can hold its own when it comes to interior quality and finish, although it's got a bit of catch-up to do in order to match foreign offerings. Consumer Guide registers a slight knock, claiming, "Interior materials quality is good when compared to domestic-branded premium sedans but falls just shy of the standards set by German and Japanese rivals."
When compared with other V-6 models Consumer Guide finds "slightly more road noise with the STS-V”—perhaps the price of firmer suspension tuning.