[nonsupremous]

I haven't tried the true high end mx series, like the 980 or 985.  I used to own the 880 but I'm not even sure if you can get them anymore.  I think the 880 was a slight step up of the 580 in overall sound quality.  bass was decent.  If you're looking for an earbud workout headphone I am also highly recommending the px685.  It's a very unique design.  Like a full size headphone with earbuds attached to the ends.  I might be going out on a limb with this one, but they sort of remind me of the px200ii.  A review is in the works.  I'm actually thinking about starting a workout review thread and see if we can't get some non audiophiles to jump in and review their favorite workout beasts.
 
And I am with you, I am not a fan of in ear headphones at all.  I love earbuds.  Comfortable, decent sound.  The only thing they lack is bass.   But there are work-arounds for that.