Polk RTi8 or RTi12? In a theater with 2 good subs

[Schrute Farms]

I have a theater that measures 15.5 wide by 23 deep, with a 9 foot ceiling and carpeted floor. I also have dual Elemental Designs A2-300 subwoofers.

Right now i have the Polk Audio RTi150 towers, and a CSi5 center channel, all three front channels are each powered by 200 watt monoblock amps. What I would like to do is to replace the RTi150 towers with either the RTi8 or the RTi12. Why not the RTi10? Because I want dual midrange drivers. I feel like my low-end is handled exceptionally well by the ED subs. I'm leaning towards the RTi8s because they have dual 6.5" drivers which are exact matches of the drivers in my center channel. The reason for this choice is that the RTi speakers are on sale locally and very affordable.

Which would you choose and why?