Don't kid yourself, the B&O lacks any kind of bass. Mids and highs are okay. Essentially, it's what a stock stereo should sound like but nothing more. I've heard it's easier to upgrade the base 7-speaker system because the B&O center speaker and subwoofer (if you want to call it that)...
Divorced too many times with too many kids to afford Katzkins but CAN afford Clazzio seat covers. Katzkins are very nice and probably have better cushioning but if you are okay with your OE seats' level of cushion and just want classic leather styling, possibly heat, then Clazzios are a good...