The CR articles (including the footnotes) sum up the differences pretty well. There isn't much to compare in the classic sense of measurements other than dimensions -- it is mostly a matter of does it or does it not support a particular feature. They all run LG's proprietary WebOS interface.
As always, the choice should come down to what looks best to you and for many that isn't always the top model (especially with the B7 in the mix).
You might check AVSForum in their Display Devices->OLED Tech and Flat Panel subforum. I've found the discussions of banding and vignetting among many OLED models to be most enlightening.
If I were forced to buy an LED at this point, it would probably be the Sony A1E. It is more money, but it is a lot more TV and the few nits that CR had could probably be worked out in firmware (if they haven't already been).
Generally speaking I wouldn't depend too heavily on high-end stuff being heavily discounted for Black Friday. Black Friday is more about loss leaders and stepping up.