Oh I love those rocks in that photograph. Actually the South of France trip was an experience, glad I went but it is not on my list of places to return to.
In my opinion
Even in September the roads were busy and it didnt feel out of season even though the French had returned to work and school holidays finished. We were delayed several hours just queuing to pay at the toll booths on the autoroutes.
Cannes is all about the money.
Nice is not that Nice.
I got great photos in Antibes and Saint Paul de Vence, the weather was hot and I was with family so all in all a pleasant experience.