does anyone here know the spring rates for the STi sport lowering springs, and the USDM STi version 8 stock springs? i know that they are both stiffer than the stock WRX springs, but i'm curious about just how much stiffer they are. i have a set of USDM STi take-off struts and springs coming, and i'm wondering if i should go with the STi lowering springs in place of the take-offs. i know that either will be a significant improvement over stock. thanks.