I finally caught this movie this evening, and loved it.
Yeah, there are a lot of flaws. The casting could have been better (except for Kato, Jay Chou was incredible, and the main villain), some story elements were just unnecessary, but dammit, this movie was absolutely badass. The Black Beauty was gorgeous, the action was constant and campy in the best possible way, and it was just plain funny at times as well. It was definitely worth seeing, especially with friends.
But yeah, I agree with the video about the 3D. It was completely worthless, don't spend the extra four bucks, even though the glasses are snazzy.