I agree with JohnK and the others, your Pioneer is a top notch avr and is more than capable of driving the M80s and a VP180. There are some gains to be had by going to an external amp whether or not you feel it is worth the added expense is up to you.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70