how responsive is the f35 in hover. especially in the roll axis. What do think of the roll posts? is it a good concept?
The pilot controls have no direct connection to the attitudes (like roll) in hover mode.
Instead the throttle and stick is used to tell the computer if you want to go up, down, forward, back, left or right.
So for example pushing stick to left by some degree tell the computer to move left with a certain speed, the computer will handle all the roll for that. So pilot controls sideways speed, not roll.
Btw. this is probable relevant to your question: How does the F-35's roll posts work, and how does its engine turn down 90 degrees?