This is just one anecdotal account, but it might be useful: I'm in my 30s, so sort of an inbetween generation in regards to facility with all things digital vs analog. There's something I've always felt comforting about physical buttons, knobs, switches, and you won't ever catch me using my wife's iPad. I was skeptical of the loss of buttons, and I was skeptical of the loss of the instrument cluster.
I've had the car for about two weeks, and find the usability incredibly intuitive and not at all distracting. It was interesting jumping back over to our Subaru, which we've owned for several years, and find myself still bewildered by their choice of knob locations and their labyrinth of screen menus. adjusting the climate settings on the Subaru--even with knobs--took my eyes off the road much longer than Tesla's menu. Now, I do feel that the Subaru's interface was particularly bad compared to most cars I've owned, but every day I am convinced more and more that what at first glance appears to be a hastily mounted iPad in your face is actually an incredibly well thought-out and usable improvement to the driving interface.