At this price point and already owning dt770, I’d say save your money until you can move up further.
I own the dt770 80ohm (old plastic version), mogami rewired from cup to cup, detachable cable and dekoni choice leather pads. I have owned the argons mk2 and the mmx300 along with the dt770 all at the same time. I have also owned the m1060c but only at the same time as the Argons. I used the dekoni choice leathers on the mmx300 as well. I am a thick glasses user as well and they were all run from Burson Play. They are all in the same ballpark but here is my imo rankings.
Bass 1060c >> mmx300 > Argon > dt770
Literally the only thing the 1060c has is awesome bass. Everything else about this headphone was average to really bad. The mmx300 has great sub bass rumble more than the Argon. I loved the rumble the mmx put out. Argon probably is better though the whole range.
Mids Argon >> dt770 > mmx300 >> 1060c
Argons sounded best here for the meat of the music. For vocals they were the best of the bunch. Something was really wonky for me with 1060c lots of shout and weirdness. Not as much difference between dt770 and mmx. Dt770 gets the nod because I don’t hear the treble as extended or the bass as boosted.
Treble mmx300 > Argon > dt770 > 1060c
Treble is well extended on mmx and sparkles. May be too much for some but it provides more detail. Argon is more subdued but provides a very pleasant experience. Dt770 somewhere in between not as pleasant as argon but not as detailed as mmx. 1060c just no.
Comfort/Build Argon > dt770 > mmx300 >>>>>>>> 1060c
Argon was very comfortable and built like a tank. Same for dt770 but due to age and mods it has less clamp than the mmx300 and 1060c. Mmx is fine but you get the volume pot cable and it clamps like a banshee out of the box. Stock pads on mmx are also pretty stiff. 1060c lololololololol. I don’t have to say anything about it’s build just look at it. Comfort was ok but why bumps ok the headband who does that?
Not going to give summary on the last two because nothing is standing out from memory.
Soundstage Argon > mmx > dt770
Imaging/detail mmx300 >= Argon > dt770
I feel that when it comes to gaming anything “competent” is fine upgrading for gaming beyond that is dumb and makes no difference.
Overall I regret returning the mmx300. I bought it new for 250 and now it’s gone up in price. It sealed the best for me with my glasses so it provides the best isolation which to me is the only reason to use a closed back. It’s mic while sensitive also sounds really good. I don’t feel the Argons are worth the wait time at this point and with the increase in price on the mmx plus the dekoni pads not sure that’s worth it either. With the wait time and extra added cost I’m not sure either argon or the mmx present great value.
Like I said I’d keep your dt770 and save your money for something that’s a further step up unless you hate them or just have to have something new.