Zach,

The Infinity system your considering offers alot of bang for the buck. Honestly, for the price and performance of a "mini" system I think it will be hard to beat. I am unfamiliar with the Polk system.

I doubt the Infinity system can or will outperform what you presently have, but for whatever reason you seem to want to downsize. Only other reasonable bang for the buck system that comes to mind is this one HERE but at about double the cost of the Infinity. This baby will rock your world, and the sub will have your mom throwing you out of the house!

RG