I've probably gone about 8,000 miles on autopilot in mine (AP1) and it is truly amazing. After a road trip stint of ~200 miles, I feel much more energized and less fatigued in the Tesla with autopilot 99% of the way than I do in previous non-autopilot cars. It really is a game changer. You may think regular driving doesn't require much brain activity, or that the Tesla cruise control and auto steering don't do much, but you really don't realize how much your brain is working to handle those things until you can take a step back and let the care do most of the work. Then you can focus on other things while on the road that you didn't realize before. The behavior of other drivers for example. I can watch a car near me with greater focus and see what that person is doing.
Regardless, if you have not driven one, I highly encourage it. You really need to take it out on the highway and drive it for 30 miles+ to really understand how amazing it is. I've driven other cars with "autopilot", and just like car reviews say, they are nowhere close. (Mercedes, Cadillac, Volvo, others with just auto cruise control). It's just one more reason why current Tesla owners are so fanatic about their car, there is nothing else like it and most likely won't be until ~2020 (maybe).