Good Place in Difficult Town
Excellent hotel, but hard to find. Do NOT try to use Sorrento as a base by car. Immense time wasted because of the traffic, both going into town and getting out (e.g. 45 minutes to go 4 km). For travelers using only the train, the town would be better; and the hotel is not far from the station. Except for the old part of town near the ocean, Sorrento is very ugly, crowded, and traffic-ridden. Of course, the general area is gorgeous, but it is overpopulated by buses, cars, and people. The Relais is well run and friendly, with good facilities and a sheltered feel. Overall, I recommend the hotel highly, but I was disappointed in Sorrento. Positano is easier to negotiate and more beautiful.
I don't know what 0-star quality is. But I think the Relais is very good for its price.