I plan to check out of Big Sur early morning. I must go to Partington Cave, JP Burns Statem Park for McWay Waterfall, and the bubblegum alley in SLO. I am interested in the Guadalupe Sand Dune. I can't tell how long I will spend stopping for scenery along the way, like elephant seals or whales or the Morro Rock. I am not bothered about Hearst Castle.
On the other hand, the stretch between Obispo and Santa Barbara does not seem to have interesting stops.
I am driving with 2 kids. I don't like driving in the dark unless it is a well lit easy drive.