If you're on an interstate highway, the car will behave like that for anyone because it's using the V11 heuristic software. But on state highways and such, V12 will be running, and it will choose an "appropriate" speed. It's frequently wrong, both high and low, leading to all these complaints against it.
I share the fear that bringing V12 to the interstates will mess up the most useful capability of FSD. In general, when Tesla implements an Auto Anything, it's inferior to my doing it myself. Not just different, but clearly inferior. Auto lights, auto wipers, auto lane selection, auto speed selection, etc. Whenever I engage FSD, I turn off as much of the automatics as I can, waiting for the day when they do it as well as I could.