Ooohh I can totaly relate to your experience with the sundaras. I have one as well, and it does well when I consider individual components like detail, clarity, and accurate bass/mids/highs. But, I'm just not enjoying the experience together as much as I thought I would, and even thought maybe I expected too much. I'm finding here that a few people have had the same issue. I got the sundaras coming from listening to a grado sr80e for a few years cuz I wanted an upgrade. I miss the grado signature sound that makes vocals 'sparkle', meaning they sound like you're at the front row, and you get the sound of someone singing directly into the mic (amazing sound for so much chaos in treble). So I played around with EQ on the sundaras to sound more like grados by referencing rtings graph. And I've been getting into auto EQ (learned about it from a crinacle video), but I feel you don't have to stick to auto EQ and the harman curve. After EQing my sundaras to fit the grado signature sound and well, it kinda worked! It turned sparkly, and resembled the grado right-in-the-mic vocals, exciting and crisp sound, albeit losing soundstage as voices and instruments sound closer to me.

Yeah so I think I still have a lot that I can do to shape the sound coming off my sundaras. Similar, but different in sequence from you, I am getting dt770 250ohms for closed backs soon and am excited to see if they are more 'dynamic' sounding as you state!