DD, if the 1500 does in fact turn out to be able to handle the M80s with sufficient power, there's no good reason to change. Keep in mind that the M80s will be using about 1 watt at a comfortably loud average level. Brief split-second peaks could use 100 watts or more, depending on how loud you play them. Also note that the amp in the EP500 will take a lot of the demanding low frequency power requirements off of the 1500's amps(this is actually a form of active bi-amping).Unused power reserves, are just that, unused, and don't provide audibly cleaner sound.
