Joined a group tour to Japan for 5 days and stayed at Sunshine City Prince for 2 nights. The hotel is big and busy with over 1000 rooms. We stayed in a standard twin room on 22nd floor. The room's small but clean and well equipped with all necessary amenities. The best thing about this hotel is its convenient location. 24-hr convenient store on the hotel lobby and also 24 hour SEIYU supermarket within easy walking distance. It's also only a few minute walk from various department stores, and train station.

I have stayed at this hotel 4 times over the last 6 years. Its getting a little tired now and I will look elsewhere next time. The twin rooms are very small and the room furnishings are looking pretty worn. It has over a thousand rooms but its a dumping ground for large tour groups.
The ONLY good thing about this hotel is its location. Situated just 5 minutes walk from the Ikebukero train station; a major hub for many lines. it is also only minutes from the huge Seibu and Tobu department stores. In addition it is located right next to Sunshine City, a huge shopping centre and it has a wonderful 24 hour supermarket across the road where you can buy the nicest freshly prepared food and heat it up in the microwaves provided. So if you can stand the rooms being small and on the dingy side; and you didn't pay too much, it does have advantages.

Stayed 6 days this April 2012. The room and bathroom smell musky, beds and carpet had seen better days. Elevators is like riding the subway or train during rush hours except you had to squeeze between luggages too.
There are no frills or service to talk about at this hotel and I would leave it at that. The only saving grace for this hotel is its close proximity to restaurants, shops and Ikebukuro station about a good 5 to 8 minutes walk.