I have been using a pair of Q701s for many years now (11-13 years now). They are getting long in the tooth - 2 sets of ear pads, a new band and I rewired them after the wires started breaking. I am looking for some new headphones. I LOVE the sound staging these guys provide and personally prefer open back vs closed back headphones. However, I am openminded toward that.
I use a Schiit Hel 2 for my DAC/Amp.
My budget is around $500-$600 USD.
Headphones I have considered - DT 1990 Pro, HD 660S2 or something around there.