Wow! The Polk Rti A9 is for sure a very big speaker.
I do agree with Peng that after careful listening, the Energy RC-70 seems to have a bit better resolution and finesse, with an overall better fully balanced sound. But the difference is not Black & White, for sure. These Polks sure can rattle your room with powerful bass.
But for my own personal taste, I'll pick a pair of Paradigm Reference Studio 60 v.6 speakers.

But, that's just me.