I have both. It's really hard to compare closed and open. But...
Compared with the Aeons, the DT 1990 pros are much wider with better instrument separation and more sparkle. The Aeons sound a little congested, relatively.
The low end on the 1990s is much more pronounced than on the Aeons (I know, odd for Beyers). They really rumble (put on Bela Fleck's Cosmic Hippo), even with the analytical pads. With the bass-boost pads they are insanely bassy. I run them with the analyticals.
So, oddly, I find the Beyers more "fun" than the Aeons. Not a long way from neutral, but just a little more bass and sparkle.
But even the best closed can is going to have a hard time competing against a good open can. I have the Aeons because I need some isolation at work. Otherwise I would only have open cans.
BTW, I vastly prefer the 1990s to HD600/650. They are equally resolving with MUCH better soundstage and a more engaging presentation.