agreed
Keio Plaza is good,
very big room, the one i stayed last time could see Mount Fuji !!!!
the breakfast buffet is fantastic too, though you may have to wait outside for a while.
I prefer Century Southern Tower than Keio. Keio only has the advantage in visiting Disneyland. In fact, there are non-stop JR shuttle buses travel from Shinjuku to Disneyland (last at 9:50am). The bus stop also closed to Century Southern Tower.
Keio is near business centre area but Century Tower relatively close to JR station and shopping core area of Shinjuku e.g. 高島屋. It is more convenient to go to other places if you stay at Century Tower. The room rate of these 2 hotels are similar. Therefore I booked Century Southern Tower for my JPN trip in late April.
I also through priceline booked CX package in very early March.
Early flight at 910 to Tokyo and late return (1700 or 1830) from Tokyo including 2 nites hotel at Century Southern Tower all-in-rate $5450 for adult and $3000 for kid