Just stayed here for two weeks. We had a triple room on a high floor to the rear of the hotel and we had a view from our balcony of the Med on one side and the mountains on the other. I will not repeat the earlier comments about friendliness, cleanliness, value and location, except to confirm that they are accurate.
Viareggio is a very good base from which to explore this region of Italy, including Florence, Pisa, Lucca and the Cinque Terre. It provides the opportunity to combine some sightseeing and culture with rest and recreation. Good variety of restaurants. We would have preferred to have a little more nightlife (music, dancing, etc) in the centre of the resort.
If you are thinking of visiting this part of Italy and are looking for a family-friendly place to stay, look no further than the Hotel Katy in Viareggio.