I have had a 51d7000 since September 2011 and LOVE it. The PQ is incredible, I really have not seen fluctuating brightness others have reported even on test clips and I have NOT applied the firmware fix for FBr as of yet, and the buzzing is really only noticeable when it is dead quiet and have NEVER noticed it while actually watching TV (as opposed to silently listening for a buzz). No peeling or cracking either.
Rumor has it from engadget the blacks are deeper on the E series but hey I have NO regrets getting this set. I say go for a D if you can get a deal on one.