Rick - When Stereophile tested the RB 1080, it delivered 584 watts with one channel driven into 4 ohms - so 300 WPC with 2 channels driven will be achieved.

The only caveat - the Rotel clips hard after that. The Maggies are susceptible to blown tweeters under clipping conditions - shouldn't be a problem for you, as the speakers will likely start showing issues at about 150 watts.

They are a tremendous speaker - but won't get loud.