This is my 3rd time at Keio Plaza Shinjuku. It is in a good location, accessible to many shops and restaurants. It is within walking distance ,about 10mins walk to both Shinjuku JR and Keio Stations. If you take the Narita Express (N'EX) then it will be the JR station. There is also airport limousine bus that will take you directly to the front of the hotel, good for those with many bags.
I took the N'EX arrive at about 11.30am. I requested for early check-in and was given a room at no extra charge. I had to move to Keio Plaza Hahioji, and the hotel did my luggage transfer for no charge.
The room is decent size and only wired LAN is provided. It was quiet and I always have good sleep there.