I can't express how wonderful the Park Hyatt Tokyo is. The rooms are HUGE, not only compared to Tokyo room size standards, but to most hotel rooms.
The service is great, the feel of the hotel is a bit stiff, but hey, it's all how you look at it.
The location is fair, if you will be in the Shinjuku area, it is great, but getting to the other side of Tokyo can be a lengthy trip. The mini van shuttle to the train station and back is convenient, and if you know the train/subway system fairly well, you can get around with no problem.
