Stayed here for 7 nights. Then location is fantastic, next to the subway station, 5 mins walk to the JR East station. Plenty of cafes, restaurants within a few mintues' walk from the hotel.
Just crossing the junction 2 minutes away is the area of well known blocks where there are possibly close to 50 or more restaurants. These cover the whole range of Japanese cuisines, from fast food to elaborate teriyaki, sushi setups. 3 or 4 convenience stores are in this area alone. There is also Takashimaya, Tokyu Hands, and a few other department stores next to the JR Shinjuku station.

The hotel itself is well kept, staff are extremely efficient. Rooms are small but that is expected of central Tokyo hotels. Those with a lot of luggage are well advised to pick the bigger rooms. The front office staff are helpful, giving clear advise on timing of Airport Limosine Bus and arranging the booking. The bus drops off travelers right tomthe door step of the hotel from Narita Airport. This is recommended over taking the trains for those with kids in tow and with plenty of luggage.

The Sunroute Plaza Shinjuku hands down a fantastic western-style hotel. I recommend anyone travelling with a friend to consider booking this hotel since the cost of sharing a decent hotel room is not that much more than getting a "private" ish room at a hostel. But the level of comfort and convenience is orders of magnitude higher.

Bathroom amenities include hair dryer, hair brushes, razors, cotton swabs. I found it interesting that the hotel staff replenishes hair combs they are being used. Overall the room was very clean, bed sheets feel fresh and crisp, and the mattress was comfortable.

Like what the others have already mentioned, the location is fantastic. It's literally steps away from Shinjuku station which gives you access to JR Trains, JR Buses, Tokyo Metro and other private lines. You are within walking distance to the tower district, department stores and entertainment and shopping. For those who like to walk, it's a very lovely 20-30 min walk to Harajuku and Omotesando as well.

There's a Denny's nearby which offers incredibly cheap breakfasts (400-600 Yen per person for a full meal with a drink included). Keep in mind that Japanese Denny's are not the same as American Denny's in that they do not serve greasy fried food. Across the street from the main entrance is a Japan Post Office equipped ATMs which accepts ATM Cards issued by foreign banks.

One thing that others have also brought up is that the area is VERY crowded, as Shinjuku is a major commuter hub. With that said, it is best to try to avoid morning and afternoon rush hour when you are arriving to check in or leaving for the airport or somewhere else in Japan. People are very polite and courteous, and they will try to make way for those with large pieces of luggage. Even if it's no trouble for them it may still be troublesome for you, the traveler, to lug your luggage between the hotel and the station.

Accessing the hotel:

The Friendly Airport Limousine can drop you right off the front entrance of the hotel, though getting into the city may be slow.

You can also take the JR Narita Express which is faster and more comfortable. To bypass some of the crowd, I would recommend exiting Shinjuku station by taking the Shinjuku Southern Terrace (新宿サザンテラス), and make a right when you see the Krispy Kreme Donut shop.

Location is a pleasant hour's ride on the Narita Express from the airport terminal to Shinjuku Station, plus a 5-minute walk. The trip is pleasanter and faster than services that use the crowded Tokyo highways, for no greater price. The only trick is orienting yourself at Shinjuku; look for a "south" exit and walk a block past the McDonalds.

My "bright single" room was small but not unreasonable for one person on a business trip. There was generally everything I needed, except that I would have liked some drawers for putting clothing away. The desk was quite usable once I moved various things out of the way; Internet (through a cable) was free and worked well. The bed was of "double" size.

Photos show a seemingly drab building but the entrance and inside are nice. The breakfast buffet (additional charge) was reasonable and in general I found this hotel to be good value for the money in expensive Tokyo.

Stayed here a while ago but I would recommend this hotel as it was in a brilliant location! The room was quite small but it didn't matter because we were out of the room all the time but you couldn't beat the location! There is a nice bar and nice restaurants nearby. I would definitely stay here again.