Marc thanks for the impressions.
I really liked the HE60 when I heard them as well. But the HE60 driver sits a similar a distance from the ear as the Omega 2 MK1 (from what I recall) and I was able to get a sense of space, soundstage and depth even with rather crappy recordings.
Using the Koss amp and my brief encounter with the HE60, I preferred the HE60 to them in every way. I used to be a very big Grado fan, but after hearing the finesse of electrostats I could never go back to them.
I definitely think the ESP/950 drivers have a lot of potential, I'd love to hear them in an enclosure where they sit a bit further from the ear and maybe slightly angled?
But the Omega 2 MK1 remain my king of headphones ATM