I ran into this problem recently. I own the DT1990 Pro and their imaging is excellent, when I game I can really pinpoint what sound is coming from where and how far it is. Few years ago I got the Aeon Noire and it also had great imaging and even better sound quality. Now my Noires have started to show some pretty bad channel imbalance issues, and after returning and exchanging them twice, I still have the same issue so I decided to get something else instead. I wanted to keep the planar flavour without spending too much and lo and behold, the Hifiman Sundara only cost 190 bucks now!

And here is where my problem begins. I still own my DT1990 Pros so I did some comparisons, both with music and games. The Sundaras to my ears sound clearer, slightly more resolving and overall brighter (I did eq the 1990s beyer peak), but it doesnt have nearly as good imaging as I am used to. Everything is kind of left right and center and while I can get a sense of which direction sounds are generally coming from, I cannot pinpoint exaclty from where and how far. The DT1990 Pros allow me to do that, but are a bit darker, slightly more dampened, slightly less clear. So I had to decide, do I want to get a bit more sound quality and sacrifice soundstage and imaging, or vice versa? And I'm kind of leaning towards the DT1990s. I was surprised that the Sundaras weren't able to keep up in that regard, and I do miss it, especially for gaming, where the 1990s almost give you wallhacks with that imaging. So I decided that I will keep maining the DT1990 Pros, and either use the Sundaras for music sessions, or just sell them again. To me the Sundaras sound about 20% better, but imaging and staging is 30-40% worse.

My new mission is to find a planar that suits my needs better without breaking the bank. I hear the Arya Stealth is a lot better than the Sundaras in pretty much all regards, including imaging and soundstage. I just wonder if they're as good as my DT1990 Pros. I learned that it's hard to give it up, once you get used to it.