I don't remember the Klipsch KG2's being available when I bought my Polk's. My Polks are the original Monitor series 5's with a passive radiator. They were just coming out with the SDA series that year.I have looked on the Polk forum several times, but have not seen any real "upgrades" for my speaker's crossover, mainly just tweeter references. I did have Polk send me a schematic of the crossover with the values on it. Handy for when I need to replace something. I'm sure it could use a recapping at least, but I hate to mess with them since they work fine as they are.