Oh man, where to start.
Well, I guess I'll start with the most logical: starters. Err.... they're alright but I'm disappointed overall. Fennekin is decent. Nothing I really hate about it, yet nothing I like either. Chespin is just not clicking with me. I admire GF for going for something very different in terms of Grass-type starters. Prior to Chespin, they were all reptilian. Now they're going mammal. However, I'm not impressed. It reminds me too much of Pachirisu, and those buck teeth... ugh. Also, I don't like the brown color. It's too dark, I think it would have looked better if it was a lighter brown, or maybe a golden color. And Froakie, oh gosh Froakie. Terrible. I usually always prefer the water type starters, but Froakie has broken the trend. Do I really need to explain why I don't like Froakie? Sigh... well at least we still have evolutions to look forward to! I have a feeling Froakie's evolution line will be pretty cool, so I may end up choosing Froakie after all. But for now if I had to choose, it would be Fennekin.
I also am not impressed with Sylveon. Its design is too cutesy and it doesn't look cool at all. I don't mind the pink, but the huge light blue eyes and the bow (it has some kind of bow or something... or maybe I'm just seeing things. I've only seen Sylveon like three times, so maybe I shouldn't be criticizing it, but still) just ruin it for me (for ME, I'm not saying nobody will like it but I sure don't). Also, I really hope they don't introduce a new type now. I think the 17 we have are good and adding a new one might make things complicated. We'll see, though.
And finally, the new Mewtwo form. It's ugly and looks like it belongs on Dragon Ball Z.
But, I will give Gen. VI one thing. The Legendary Mascots look awesome. I love Xerneas and Yveltal!
I'm excited for new information and I'm sure that for every poorly designed Pokemon, there will be an awesomely designed Pokemon to make up for it.