I've finally finished Baten Kaitos. It took me about 70 hours to do so, in 3 months. I am happy to have played it, since it was a great game. The card-battle system is a very good and it was something very new for me. And the game looked and sounded very good too.
There were a few minor points too though, and I personally liked Tales of Symponia a little better, but it's still a wonderful game that any RPG-loving cube owner should try. I can't say whether I'm going to write a review about it or not, but for now, I rated it 9,5.
Edit: Well now I have reviewed it, and the score that lead to is 9,6. Like I say in my review: every GC owner who likes RPGs and is not put off by a card system should play Baten Kaitos :)