At your guys' recco, I pulled the Timeless from sale here, opened them up and am listening now (none of my other mmcx cables seem to fit, tho that doesn't surprise me) with the stock cable.
Glad you guys convinced me...at this price point, or at 10x the price, they do sound excellent and are able to stand with my kilobuck sets very admirably!
Listening now thru my P6Pro and I have zero complaints, even after exclusively listening to Mentor for the past several days! Thanks, guys!
Now I may have to explore the cable upgrade
as it seems it could open up the stage a bit, but they don't even have an hour on them yet, so let's burn them in!