Articnoise
Headphoneus Supremus
I was really asking whether there are any substantial differences.
Mine are 3 years old. The price in Hong Kong to replace the drivers is HKD6,000 (USD1:HKD7.5)
The differences is substantial IMO. The sound still have most of the musicality, fullness and richness from the older revisions, but with more air, less grain, blacker background and clearer sound all across the FR. The high treble is more prominent and contribute to a clearer and airier sound. It also make it less forgiving of issues in higher FR than the older revisions. For me it has been a clear step up in SQ with the latest revision. The difference is IME as substantial as all the previous revision combined.