Here's a new "feature" that I just discovered in 8.0 that limits AP even further:
On undivided highways where AP limits TACC speed to the speed limit + 5mph, engaging Autosteer now only allows you to set TACC's max speed to 5mph over the limit.
In 7.1, you could set a higher speed (e.g. 50mph in a 25mph zone) and engaging Autosteer limited the car's speed to 30mph, but this didn't change the 50mph max speed. Then once the speed limit was lifted to a higher number, the car would automatically accelerate to the new limit (5mph over, or 50mph, whichever was lower).
This was useful in situations such as temporarily driving through a town with a low speed limit. However if you now engage full AP (TACC + autosteer) while the limit is low (say 25mph), the max speed TACC will get to is 30mph. Pulling the speed stall up won't allow you to go higher than 30.
So after the speed limit changes to a higher number, the car will only go up to 30mph even though the new limit might be much higher, such as 55mph.
I haven't tested the situation where AP is engaged with a higher speed and a lower limit is encountered to see if the max TACC speed automatically lowers to the new limit + 5mph, or stays at the original TACC speed. I would assume (hope) it doesn't change down, but as it is this new "feature" seems like another step in the lawyer-mandated CYA direction..