I have a pair of Polk r25's and I agree; they sound really good for the price. You have me on the Pi 2's I haven't heard them but I lived with Heresy's for some time. I liked them. Can I say one thing here; the Klipsch K2g's; have you ever heard them? I sold my pair and now I wish I hadn't; I think they are better than the Heresy's. They are as efficient and usually sell for about 200$ on the 'bay. They have that little D-Horn and a passive radiator.On the Polks; there is a Polk forum; I have searched for anyone who might have tried mods on the crossover on those. Ever see anything along those lines? That is one nice little speaker. Huge bass output for a tiny woof.
Lot of speakers out there.