...okay, I've stood there in front of them, looked at them both playing the same HD video, and can't see a lot of difference aside from $800 of pricetag.  I know the 6 (and 7) series do the 100hz frame interpolation thing, and the 6's theoretically have higher contrast. 

So, those of you who have fiddled with these things: Does the 100hz thing actually make any difference?

AJ