I have the 1990s and then got these 770 Pro Xs for the same reason, isolation (for recording) and your assessment is spot on. I could have written this review, lol! I use an RME Babyface Pro FS interface in my studio and on the headphone channel of the software I do have an EQ that cuts the 8.5KHz harshness of the 1990s but it's too much for the 770 Pro X. I think I'll run the 770s stock for a while and let them break in, and just keep them a little sizzly since I don't mix with them. But the soundstage and detachable cable and confort are worth the price of admission. There is one thing I can't stand: the provided cables, both in memory and how tight the connector is. I ordered custom cables from
Fog City Audio with real Neutrik connectors and when I switch headphones the mini XLR plug going either way is like butter.