Oh yeah, the artstyle has nothing to do with the quality of the rest of the game, including the story. It's simply something that I personally don't like, but that's just how things are, some people are going to like it, others - not so much.
I absolutely hate the brown look of Torment, for example, yet it's one of my favourite games and features a brilliant story. The art in D:OS is one of the things I dislike about it, but the rest of what they're offering seems interesting to me. Larian's games have been consistently good, so I have faith in them. BioWare, on the other hand, have made a few missteps that really put me off their last few titles, so I'm more apprehensive about what they have to offer.
They do need to work on their environment crafting skills, however - they just don't feel right. Generally speaking, it's been a weakness in their games ever since they moved away from the Infinity Engine. The swampy area, which a lot of people here seem to like, does look pretty good though, so they clearly are making progress. It might be the result of the Frostbite 3 engine being better for darker, more realistic environments, that makes that area in particular stand out. A clash between their artstyle and what the engine is good at rendering might be responsible for other areas looking a bit weird.
