I do prefer the non-cartoonish animation. I think the DF would work really well if done like Castelvania, but a bit more realistic with some of the settings, weapons, and such. A lot of that animation, the weapons, clothing, and setting is just ludicrous. Another advantage to an animated series is you can have characters age at the right rates. The immortals don't age, Harry ages slower, and regular mortals age regularly.
The problem with animation is that a lot of people will never take it seriously.
I don't know if doing it as an animated series would be a problem or a benefit on the business side of doing a series that covers 25 novels. I wouldn't be surprised if we never get a full Dresden Files series adaptation. Has anything that big ever been attempted? Some quick googling puts A Song of Ice and Fire at 1,770,000 words and DF at 1,997,201 words as of SG. Not counting PT, BG, or any short stories. And we're still about eight novels from being done. Three of those novels are supposed to be big door stopping tomes. Conservatively, that is going to be over three million words.