Thank you for your readership and your support, both here and on Ko-Fi! I really appreciate your recent donation!
I agree that the Monoliths have a smooth, "non-immediate" sound. I think that's part of what I personally enjoy about them; it sounds more like a pair of speakers in a reference mixing room than the intense monitoring quality of a pair of standard studio headphones.
Forgive me if we've already talked about this before, but have you tried the HD560S at all? They have a very close level of sound performance to the 600 series, but with more width in the presentation. I think they'd be a good middle ground between the Monoliths and the 6XX, at least for my personal tastes.
Thanks again!