100$ for a fkn paintjob? seriously? I bought the DT990 pro limited Edition (also completely black) for 140€ on Amazon.
Here they are for 172$ and free shipping: http://amzn.to/2er6BiZ
Of course they look different, (imo the pro look even better than the premium) i tested the pro and the premium and couldn't hear a big difference.
So, the premium would simply be a waste of money for me.
Yes they do, if you choose models with different ohm ratings. They both have 250 and 600 ohm variants, and actually using them shows an identical sound with potentially slightly more bass in the premiums due to slightly different build design. I really don't know where you're getting your opinion from, it definitely isn't from personal use or real research.