Polk DXi's here. I've owned Polk home audio and car audio and have never been dissapointed with any of their products. Thats close to 20 years of using their products. Rockford Fosgate amps here, same reason (car audio). First venture into Kicker with 2x10" subs as of last month. Pleased so far. Regarding online purchases, used Crutchfield for several years now. Customer service top notch and handling/dealing w/ issues, they have always been helpful.