Not specifically M6 related but...
Borrowed a friend's BMW X a few weekends ago. (Actually she borrowed my pickup truck and left her X5 with me.) I've had a couple BMW's in the past, but none recently with the new entertainment/nav/control system.
Holy f*** confusing! The BMW controls and displays were so un-intuitive. And the little screen for the nav and nav diagrams were garbage compared to the MS.
So this past week her husband borrows the truck again and leaves a Mercedes C class. Was not impressed compared to the MS. And what's the point of having paddle shifters if it defaults back to automatic when you rev high and don't upshift! At least the entertainment/nav controls were better than the BMW ;-)
I've owned over 25 cars so far and driven 100+ different models, years all over the world including Lada (a *sugar* box) from Russia.
Nothing comes close to a Tesla what so ever for its intuitive, modern driving experience.