Started in Roscoff and headed along the west coast initially, then headed towards the south east coast to a small place called Vias (near Beziers). Just a short walk from the mediterranean sea. Essentially bisected France.
Millau was only about 120kms away so had to do it. Ended up crossing it 3 times over 2 days. The roads leading to Millau were stunning - carved out of a mountain side with several tunnels. We had lofty plans of exploring the ardeche gorge and the pyrennes but weather and time went against us. The south east suffered unexpected heavy rain and flash flooding while we were there so it hampered plans. Could've done with another week to explore.
The Harley was a great laugh. Ground clearance was it's real only downfall (that and vibrating my gear lever loose!). Piece of piss to ride at town/city centre speeds and it held 160kph without a hiccup and that was pretty much our cruising speed for the trip when we had to crunch miles. Surprisingly competent overall. I think the most we did in one day was 700-ish kms or thereabouts.
Thoroughly recommend French roads. They're maintained to a very high order, don't have much traffic and seemingly have abit of fun designed into them.