Stayed here on a 3 night award in March 2019. Location is good with lots to see a few minutes walk away near Shinjuku station. Hotel also offers frequent free shuttle to that station.
As a diamond was upgraded to a Jr. Suite on an upper upon check-in. Did not request upgrade, was offered pro-actively. Room was fresh and well maintained. Very large with a nice sitting area.
Free breakfast every day in the main hotel restaurant was an excellent buffet. They also have a free happy hour in the bar from 6 to 8 pm for diamonds. Beer, wine, soft drinks and pour your own liquor as well as a small snack offering.
I would definitely stay here again. Great location and excellent service with all the perks as a Diamond.