Jeez, I suppose I have to burn mine in for longer then, and keep waiting for differences, hehe.
Bio-cellulose is bacteria cultivated in a lab for days then compressed into sheets several dozen times thinner than a human hair, these sheets are treated with an alkaline or oxidative solution, then cut and pressed into the desired shape as an acoustic driver.
The Sony Research Centre experimented with and listened to a lot of materials, they placed very high esteem in the sound of these bio-cel nano-sheets. If not, the R10 would have been made out of crushed rubies instead.
I'm sure Fostex and Vsonic have 'cheated' in the bio-cellulose process, and they're layering it on top of of PET or Nylon, or skipping the alkaline process or whatever, but the GR07 MK2 sounds pretty nice and has a few unique assets in it at least.
If you want to read more you can try searching for Y. Nishi, M. Uryu, S. Yamanaka, K. Watanabe, N. Kitamura, M. Iguchi and S. Mitsuhashi.
Another piece of equipment you can still find from this era is the Sony SA3000 headphone. As far as I know it's still being made in Thailand.
You can say the R10 led to the Vsonic GR07 MK2, and the Qualia 010 led to the SA3000.
The SA3000 rivals the Audio Technica AD1000 and it's excellent for the price. Similar to the SA5000 the SPL of the bass is very low, however the quality is very high, and it's very suitable for electronic music !!