Loved the location! 5 minute walk for Ugusuidani Station, which is just one stop from Ueno Station if you plan to visit for the Cherry Blossoms. It's about a 2 miles away from Sky Tree - good jog with some excellent scenery along the way.
Only the front bedroom has a window for natural light, but the unit is still well-lit. I imagine most travelers will be out during the day anyways. Beds were very soft and pillows were firm. The walls are thin, but this is true for most Japanese units. Just be considerate of your neighbors - ours were great.
Thank you and hope to visit again soon!