I have a 63" TV and you can tell a little difference between 720 and 1080. Big difference between DVD and HD.
Apparently, those of us that think we can see the difference of 1920 x 1080 moving pictures vs. 1280 x 720 pictures, can't really see the difference because Apple says so. As soon as Apple rolls out a 1080p

TV though, everyone here will be gushing about the higher video quality and we'll all be able to see the difference... and stuff like "the chart" won't matter, nor the bandwidth arguments, nor the file sizes, etc. Until Apple says so though, those of us with opinions that differ from Apple just have to be wrong about what WE want.
When video made no sense on iPods per Apple, it made no sense to Apple cheerleaders either. Then, when iPods with video were rolled out, the cheerleaders gushed at video on iPods. When iPads launched without a front-facing camera for video chat, the cheerleaders passionately argued against the idea that such a camera made any sense for those that desired it. Now that it is obviously on the way, they look forward to the new iPad with facetime. Apparently, whatever Apple says is THE way... until Apple changes it's mind- sometimes a flip flop... and then that becomes THE way. No individuals can have a differing opinion- even for themselves- and be right about it.
Back on topic though: as an owner of 2 current gen

TVs, the things that

TVs do, they do very well. If you buy one understanding what they do- and what they can't do- and you're happy with any of the compromises (such as 720p vs. 1080p, etc), you should love the purchase. My now outdated models are terrific for what they can do.
It only took 4 years for Apple to upgrade the video hardware from 720p24fps to 720p30fps. Maybe in 4 more years, we'll finally get the terrific Apple UI on 1080 hardware such as <$100 boxes from Roku, WD and a few BD players. I so look forward to an Apple UI on an iTunes friendly & (fully) compatible platform with a full HD capable chipset. Those happy with 720p would still get every bit of the 720p experience, because better hardware can always play less intensive software. So everyone will win when the THAT version of

TV arrives.
In the meantime, those of you who have bought this one- or even the prior incarnation that I have- enjoy it. For what it can do, it does it really well.