I'm split between these, the 600's and the HE400i's. I've been looking into loads of different reviews and the general conclusion I've drawn is that neutral is more analytical and coloured is more 'fun'. I also looked into AT's R70X's, which are even more neutral than the 600's, and I hear they make things sound sterile they're so neutral, which is why I'm being drawn to the 650's, which aren't so coloured they wouldn't work with specific genres. I'm just someone who listens to music, so I don't need something super neutral, I just want something I'll have fun listening to.