Be careful of location when renting. If daytrips are part of the itinerary, you want to be in the area between Piazza Tasso and the Sorrento bus/train station, or possibly on the other side of the piazza itself in the middle of the Old Town. On the main drag to the east of the station things appear to get pretty rundown pretty quick. I'm sure still safe, but still you'd like to have an idyllic look at something!
We stayed at a B&B a couple doors off the piazza, and while it was fine, it was the least favorite of any B&B or apartment we've stayed in Italy by a long shot. While technically the B&B was as described on the 2nd floor, it was a real P.I.T.A. with stairs, winding walkways. And one of our excursions--a cooking class at a working farm out at the tip of the peninsula--was cancelled without notice, and they tried to push us into another cooking class at a storefront in town, which we politely refused. Went to Positano instead and had a great time.