Swapped from AKG K702 to some DT 990 Pros and they are much better, tighter fit, more comfortable, better sound positioning too.
Popped in to post my set up as it's the first time it's changed in years and this is the most recent post, uncanny.
I have been running a Beresford TC-7520 DAC and opamp rolled to a Lm4562NA with AKG Q701's for years and loved them, especially for their positioning with regards to the Q's.
Recently I built myself a WHAMMY class A headphone amp and have been loving it, this pushed me to invest in some new cans, I wasn't interested in replacing the Q's for gaming so went for some Thieaudio phantom planars. The phantoms are fully modded and i enjoy the sound but the airiness of the Q's was so missing, the Q's sound so clean and open and the Phantoms just lacked this, while telling a friend about my purchase he reminded me he had some DT990 250ohm's he didnt use any more that had barely any runtime on them and i was fortunate enough to get them for the price of a beer (when the bars open). First listen didn't inspire me, they sounded boomy, mids got lost in the bass and it felt like the driver just couldn't keep up with everything that was going on when the sub bass hit hard with them sounding closed in and not what I expected from anything even remotely open back'd. Being someone who can't leave well alone and getting them for free I immediately ripped them open and gutted them, I removed a large solid white plastic disc form the inside of the housing, a foam disc from in front of the driver which I placed back inside the housing where the white disc used to be and a small disc of foam back infront of the driver where the larger used to be, I have to say I love them now, makes me kinda wish i didn't drop 330 for the Phantoms if I'm honest.
They have plenty of punch without being boomy, they sound more open and airy though not on par with the Q's though they do fill in the gaps that the Q's lack with regards to bass and have tons of detail. I wouldn't advise someone with new ones to try this but anyone with an old pair that fancy's trying something new definitely give it a shot, warranty will be void, be warned.
So I run, a WHAMMY the DAC in the TC7520 and some modded DT990's for gaming and music, some Q701's for CSGO only and some Thieaudio Phantoms modded for music.