Have been several time to that Hotel and never been disappointed. I would rate it a 4 Star Hotel according to international standards, Hotel offers most services you may need during a business trip and provided you do not want to spend major leisure time there.
They have got larger and smaller rooms, if you require something coming close to international / U.S. sized rooms, you may want to mention that at the time of making your reservation.
Breakfast seletion was ok for me but others may find it somewhat limited. Breakfast room can be crowded during 'peak hours'

Hotel is conveniently located above Shinkansen-, local train and subway station - perfect if you travel in and out of Shin Yokohama by train. Convenient stores, restaurants and Starbucks in the same buildings, a few floors below the Hotel which is located in the upper floors of the building.

Just returned from a business trip and spent 1 week in the Associa Shin-Yokohama.

What can I say? I had the perfect stay at this hotel and there are only very little things to criticize.

First of all, upon arrival at Narita Airport there is a limousine bus that takes you directly to Shin-Yokohama station (around 105 minutes depending on traffic conditions). The hotel is literally built inside Shin Yokohama Station and occupies parts of the 10th to 19th floor of Shin-Yokohama station. The other part is an electronics shop called 'Big Camera' (floors 3 to 9 if I remember correctly), a Takashimaya Food Center, a book store and also restaurants on the 10th floor. So, transportation, shopping and dining are all in one building.

Now for the hotel: Check in was a breeze very friendly and I got a room on the 19th floor with excellent view. There are basically only two downsides as far as the rooms are concerned:

1.) The rooms are tiny and very small so that there is hardly any space to put your suitcase.

2.) There are only 2 English TV channels (CNN and BBC News) - not exactly the most exciting channels to relax in bed after a long day in the office, but well, there is free internet which serves very well as a window to the English speaking world.

Apart from that, the bathroom has o.k. size, is well equipped and the bed was one of the most comfortable ones I ever had in a hotel. Everything is extremly clean and well maintained so that the hotel looked like brand new to me.

I did not try breakfast in the Associa Lounge on the 12th floor, so I cannot commment on the food quality.

All in all: An excellent experience in a great hotel in a central location.

Good overall deal for this hotel.
Clean, perfectly located (just above the Shin-Yokohama train + Shinkansen station) and in the same building than Bic Store (7 stories of stores and restaurants) and relatively cheap.
Bad side is the service, very minimal. The breakfast also is poor.
But for one night in Yokohama, for business, I recommend!

This hotel locates right on top of the Shin-Yokohama station (10th floor above), it is very convenient if you plan to do a lot of traveling in Japan. The hotel room is on the small side, the working desk is very small, especially if you want do some serous computer work. Internet speed was good. Breakfast selection was adequate but not very impressive. Hotel staff were very polite and helpful.