i actually really liked the o2mk1 that i heard during canjam. to me, it just sounded a lot more natural compared to the hd800 ( i did not want to leave madmikey's setup or the summit-fi room during canjam). the mid and highs to me just sound sweet. i cant explain it, it just sounds so sweet, so perfect. the hd800 on the other hand, sounded plastic to me (don't flame me, everyone has their own taste). the mid and high did not sound natural to me at all. btw, the sound of akg k70x does not sound plastic at all to me (they have this studio monitor-ish sound to it, hard to explain). as for the bass on the two, i dont really remember but if anything they are both adequate and really good that i did not pay attention to them. i feel it might be too early for a lot of comments on the hd800, as i believe they are not burn-in yet?