With stock 727, SR-007 sound a bit bland, lacks dynamic, not very controlled in the bass and kinda shouty / harsh in the high mids / treble. I would'nt say they're horrific, but the so called weaknesses of the headphones are way too present, and it's undoubtly a (very) disappointing pairing for the price.
With my SRM-1/mk2, sound is more linear, no more bloating bass or harshness, but dynamics aren't really there neither, relaxing when I'm in a good mood, boring otherwise. You really want to kick them in the ass..."wake up, boyz !"
I recently began to hear SR-007 shining with my modded 727, at last some pleasant dynamics and linear FR (with a not too weak source, gain is low on SRM-727), but their "sound-behind-a-tainted-glass" nature is still there.
I'll wait for the arrival of my BHSE, but until now, I'm not really convinced SR-007 are able to reach the slam (especially in the bass...slam, not amount of !) and the lovely involving nature of SR-009.
Ali