Thanks for the suggestion. I'll look at the HP200.
I understand that soundstage isn't necessarily better. But I have enjoyed the opens that I have tried even if they weren't for extended periods of time (the Grado SR60 is the only one I have borrowed for a while). I am definitely planning on buying a pair of Grado SR80s as well. The other part of it is that I will be buying used and used DT990s are significantly cheaper from what I have seen then the T70.
As far as power, right now I have a Schiit Magni 2 and a Bravo V2 (which I am going to modify) but one of my next upgrades is to build a Bottlehead Crack.
I also was considering AKG K701s instead of the DT990s.
I own both the AKG K701 and Beyers DT880 Pro 250 ohms, and have just sold the AKG Q701.
I'm currently testing a pair of Beyrs T70 p 32 ohms.
I play all on two rigs : one rig with a Schiit Modi 2 & Magni 2 Uber on Linux-based machine with ALSA output, the other with the Roland Mobile UA-10 on a W7 Pro 64 machine with ASIO output.
1st comment on the AKGs : the Made in China versions either the Q701 and K701 or 702 do not sound as good as the ones made in Austria. For no reason, and that was the reason or which I sold the Q701, I would buy an AKG Made in China. If AKG is the one I want, I'd buy the made in Austria version.
2nd comment on AKG K701 Made in Austria vs. Beyrs DT880 Pro Made in Germany : they sound different, really, I cannot say I prefer one vs. the other. I can keeping switching between them whilst I prefer the AKG if I want more "air" in my ears and the Beyers DT880 Pro if I want a more intimate listening session.
3rd comment : Beyers T70 p 32 ohms vs. Beyers DT 880 Pro 250 ohms. On a smartphone, there is no match, obviously. On sedentary on either the Magni 2 Uber or the Roland Mobile UA-10, they are very close, really very close in terms of definition, the 250 ohms offers more "solidity", you hear there is more "foundation" in the music, sensation which is surely related to the differences in the ohms.
One ergonomic issue with the Beyers T70 p for a sedentary use : the 5 ft cable, which is definitively too short.
(However I do not know if this 5 ft cable comes also for the T70 250 ohms version, may be-I hope not.)
Hope this helps.