I always automatically assume that everybody is always using EQ to flatten their headphone response. I can't understand how someone would spend any amount of money on headphones and then not try to get the most out of it. Even the HE6 and the HD650 sound pretty bad to me when I turn off the EQ...
To come back to the sense of "excitement", I can relate to that. I get it from my speakers, but missed it on my HE400i 2020. I increased Oratory's 10k high shelf to +2db (from 0.5) and it got closer to what I thought was lacking, but any more was making it too bright instead of bringing any more excitement. The HE6se come closer to my speakers at least, but still not 100% hit the mark. I wonder if this is caused by cancellations similar to what we actually see in the measurements, what doesn't occur when listening to speakers.
Well I posted the measurements above, 5db of difference between left and right ear is unacceptable to me. They do sound fine (with EQ that matches the channels), but this kind of defect is not something I want to have in headphones I own. But you're right, I should just return them and hope for a pair with good channel matching. Maybe I can get one which is as good as my HD650 in that regard