I have just purchased the CTEK 7, and will be delivered next week.
Recently I have found that, when I take the long trip from Windsor to Devon to see the children, or the 50 minute drive to get to work, everything on the car works fine. Doors lock correctly, camera is fine, warning lights are gone.
I can only assess that due to the distance I am driving, the battery is getting sufficient charge, and therefore I have invested in the CTEK 7. I will update all on whether this has a positive effect.