My wife and I have just spent 10 days in this hotel and we're definitely not going anywhere else next time we're in Montecatini. The reason is a mixture of the qualities of the hotel and those of the staff.
Not sure how to say this without sounding too corny, but we've never met a nicer family of owners! Seriously, they were absolutely brilliant! They helped us pick things to do around the city, as well as directed us to some super cool walks outside. The hotel itself was right in the middle of things, less than 5 minutes from the Montecatini Centro train station and about 10' from the other train station, the bus station and, if you're walking in the opposite direction, to the main park and spas.
We were also quite impressed with the city itself. It's rather posh in parts and there are plenty of restaurants, cafes, bars, icecream places and the like. Some of you may need to be aware that it seemed to be a popular destination for school-trips in April which tend to get quite loud (it didn't bother us too much, overall).
If you're looking for thermal waters, Grotta Giusti (a short bus-ride from the city) turned out better than anything we could find in Montecatini in April (quite a lot of places were closed and what was open seemed to be aimed at people needing therapy rather than fun). Moreover, Montecatini is 40' on the train from Florence (direct line), less than 1h30' combined to Pisa (change in Lucca), and there's lots to do in the neighbouring medieval towns if you're into that scene (Lucca is a good place to start).
Looking forward to my next trip.