First of all, I've never viewed either TV. My family does own an older Samsung, though, which we love!
Two outside threads already devoted to this topic might interest you:
http://www.avsforum.com/avs-vb/showthread.php?t=1019413
http://www.avsforum.com/avs-vb/showthread.php?t=1003472
From what I can gather in my quick research, the main specs between the 6 and 7 Series televisions are quite similar. Here is a link to a direct comparison on Samsung's website:
http://www.samsung.com/us/consumer/s...LN52A650A1FXZA
Dynamic Contrast Ratio,
Response Time and
HDMI inputs are the most important factors to consider IMO, as the other specs are so similar and/or inconsequential they just don't add up to much.
$2600 CDN sounds like a good price to me. I wouldn't say
great price though, since I don't really know what the market's like for Samsung Series 7 TVs in Canada. [I do know that the LN52A750 is going for $2200 at CircuitCity.com, for a U.S. comparison.]