If you decide decide not to rent a car, Buonconvento is a good base. An attractive Tuscan town, with good bus and train connections to other towns. There are direct buses to Montalcino, Pienza, and Montepulciano, and also to Siena, where there is also a train connection. You can even take a longish train ride to Florence.

With a car, you could see more in one day. By bus, you could maybe visit Pienza and Montepulciano in one day, because they're on the same bus line, but even that might be difficult.

Bilboburgler, you spelled Buonconvento perfectly.

:-) Grazie

In the CT, the trail from Corniglia to Vernazza is also open. We just did it and I found it to be fairly difficult. The views were beautiful but quite a few people we encountered on the trail were commenting about how it was much harder than they expected. One woman had my laughing when she asked if we had met any Italians on the trail (we hadn't.) "They know more than we do," she said.

Back when we hiked 4 out of 5 villages, we saw so many Italian hikers in alarming footwear. Women in stilettos and Sunday dresses! No kidding. We were able to start in Riomaggiore and went as far as Vernazza before giving out and having a gelato. Hike between Manarola and Corniglia involved a major workout with a hundreds of steep stairs between the Corniglia train station and town. We happened to encounter an outgoing red headed young man who was shuttling passengers between the town and the station. We cheated and hopped in his minivan for a ride up. It was definitely worth it.....