Got these in today, and the first word I would use to describe these babies is "clean". Good rumbly bass and sparkly treble, but as others have mentioned, vocals can appear pretty distant or recessed, and distorted guitars don't have as much of a "vomp" factor. I haven't experienced any of the fatigue of the treble, but I think I'm just not as sensitive (not sounding good, I'm 21!). I'm about to A/B these with the FXT90 soon.
Definitely the best $20 I've spent on audio thus far. I'm actually thinking of giving these to my Dad; he has minor hearing loss, and he liked my FXT90's for the detail that he isn't able to get out of his bassy sennheisers. I think these would be perfect for him, ALSO because he's a very value-minded person. :)