why bother with Hilton Tokyo ???
Unless I "must" stay at Hilton Tokyo due to a Gold/Diamond requalifying issue or something, I would not waste my money at Hilton Tokyo.(crappy location) In my opinion there has to be a lot of better valued hotels in Tokyo. In fact, Yes Shinjuku is a very fun place, and Yes the hotel is "in Shinjuku area", but it is so inconveniently located that you have to take their shuttle to/from the Shinjuku station every time you go anywhere, unless you like walking a lot or using taxi cabs.
Overall, I would rate the hotel as the last place among all Hiltons in Japan.
But again, this could be just me. Try the place and let me know what you think.