Ignoring the mmx300 here
I mean if they are talking frequency response wise the 880 600 ohm is more even, but the 1990 is no slouch either and for music enjoyment I would rather take the 1990. For studio though I would rather take the 880 600 ohm. Also I can see metal saying that but I thought dms liked them?
Here is a comment from him about the 1990 lol