I'm surprised by how much these cans are growing on me. Initially, I thought I'd never get used to them and would have to forever EQ them to get at least some enjoyment out of them. But, at this point, I'm almost fully used to how they sound un-EQd.
Do I like them as much as the CAL? I wouldn't say so. But they make an OK companion to them.
The S680 have become my go-to when listening to bright, harsh-sounding recordings; albums mixed in mono; and albums that fall into the rap and electronic genres. They fare well with some rock and metal but, IMO, not much of it. This is unfortunate for me since I listen primarily to stuff that falls into the rock genre. I do, however, listen to electronic at some point every day and, from time to time, rap so I do have a use for these 'phones. If you listen to rock and metal I wouldn't recommend these cans; if you listen to rap and electronic, these should appeal to you.
In a while I'll be using them to watch the movie Drive. That should be interesting . . .
By the way: they no longer cause me discomfort. I stretched the headband a bit by placing a few thick books in between the cups and leaving it like that for a few hours. If you, like me, have a big head and they cause you discomfort, I recommend you try that. It worked wonders for me.