IMO electrostatic technology is so overrated on this site it's not even funny anymore. I cannot speak for all Sennheiser guys around the world but it seems our local Senn. representatives agree that HD650 can be comparable to the mighty HE90. Maybe what's just needed is a special "Head-Fi edition": HD650's drivers enclosed in real carbon fiber housing with a titanium headband and of course leather earpads, the whole thing sold at $2,000. I can guarantee you that opinions will be differents!
Now about HD700, i'm almost sure that when it (if called HD700) will come out people will immediately lust after HD750 or whatever and suddenly HD650 will lose their infamous bloated bass and rolled off highs to become the best dynamic Sennheiser 'phones.

Head-Fiers are so predictable these days...
