Hello,
Not yet played at E6.
But it's planned as soon as we finish the RotR (2 books to go!). Maybe even sooner. No new feat or other mod intended about school powers or wathever.
Still, there's plenty work in adapting scenarios/campain/adventure paths to E6. ;)
Why will I play to E6 ?
Had I heard of the E6 mod before, that I would have played D&D3 (and wathever followed D3.X, Pathfinder, etc.) far sooner and a lot more.
Flavor speaking, it meets more my group's expectation.
I still remember my first D&D campain a few years ago. After a character death (against a dwarf-tieffling sorceror who was staining his clan honor and haunting a part of the mines of this clan) my players were really shocked learning that a character could be raised from the dead. ^^
"You can be raised from the dead ?! And so easily ?! So what's the point of the game if you can do anything without consequences and the death means nothing ?!"
And I realised that I was agree with them.
Maybe it's because since recently, we played exclusively rp games which don't have the enormous power increasing curve of D&D (which goes from the peasant to the demigod)...