i run kingpin MT amazons too, and i find them ok on the road, both dry and in the wet, bit noisy if owt, but you get used to it, and i drive quite hard.
I do over 80mph in mine quite often and dont worry about them, its only from prolonged hammering over 80 that they might blow or rip some tread off, cos of heat build up.
Very good off road performance too, good tread pattern and excellent grip, oh and cheeeeeeeeep!
Craig