I... don't really prefer either. I like them both as much as eachother! Both are valid graphical styles, but they're different enough that it is kind of unfair that people are comparing them...
That said, I would probably have to say I like.... no, see, I can't make myself choose. I don't know. I like both.
TP's style always creates quite a dark and sinister mood, but also manages to create a surreal beauty in the Twilight, and up Snowpeak, and felt Zelda-y, whereas this style is vibrant and impressionistic, everything's been light and beautiful so far, but it also has the potential to creat some really atmospheric creepy dungeons, like WW did, and it also feels Zelda-y... so it's darn hard to choose.
Let's look at this a different way then: I was
expecting to see improved TP graphics, and would have been cheering like mad if they chose those, but the SS style has grown on me so much now. I
suppose I'd have to concede that I do prefer SS's a little better, mainly because I'm a sucker for more surrealistic styles
Also: TP trees looked rubbish, SS tree look niiiiice. XD