Nice place with big, clean apartments, great views and friendly staff. Enjoyed the terrace with sea view, good value overall.
Not sure if it is really up to 4 stars though - the breakfast options are rather limited, and not what I would expect from a 4 star hotel, furniture and bathroom rather dated, the shower regularly went cold after a couple of minutes, the hot tub wasn't warm enough (yet, probably - we visited in May). Reception was often closed even during the day, the fitness machines in the gym were off without any explanation provided on how to use them.
Canneto is a nice place - the beach which we haven't tried but looked ok and seems to be its main attraction - but I don't recommend staying there unless you rent a car or a scooter. There is a bus to Lipari which has much more choice in terms of restaurants (and the port of course) but the last one is around 8pm already and taxis are not cheap at around EUR 15 each way.