Just got them strictly for mixing duties.
I also have the HD600 (had them for almost 30 years) and ATH50x (junky phones for vocal tracking, not even worth mentioning).
Love the MDRs at the first listen. Much, much better than I expected. Crystal clear. Switching between the HD600 it's really night and day. HD600 extremely soft and lacking any detail for critical listening. For years I thought they were pretty good. Today I listened to the MDRs, and HD600 are retired, instantly. Not a chance for them. Crushing KO. Lights out.
But I can hear immediately how fatiguing the MDRs are for casual listening. It's a big mistake to buy them for just music listening (or for prolonged listening of any kind). It's when you do critical listening you don't really "listen to music", you're constantly scanning the spectrum for artefacts, frequency imbalances and that stuff so it's not fatiguing in that way as your brain processes them differently.
But the clue is right there on them, it says right there in big letters on them, "Professional". Should be a red flag for most. This is not a consumer headphone in any shape or form. It's also not going to benefit beginner producers, may be too early for them to appreciate what these bring to the table.
I keep listening to them, and am still wow'ed. Wish I didn't listen to nay sayers and got them years ago. Absolutely amazing. They also have a funny price tag. $89 for this level of audio? Absolutely ridiculous.