Just done this route today. Perfect weather and no traffic. Some sections have been very recently resurfaced and a good percentage of the route is billiard table smooth.
I have to admit to being a bit of an impostor, I did it in an Elise SC but we\'re singing from the same hymn sheet!
This route is an alternative to using the busy N21 for Bergerac to Perigueux. Approximately 2km north of Bergerac bear right onto the D21 signed for Vergt. The road from this junction is really quiet wide and smooth. The road follow a river for most of the route and twists and turns with it the first 30k is fast and open until Vergt. Once through the town of Vergt the road becomes more twisty with tighter corners and less in the way of straights. There are a number of small villages with roadside cafes, Vergt has all the ususal shops and eating establishments you might need.