Since I've been a PC gamer for a really long time, I can start telling the difference even on screens smaller than 30', of course, it also depends on how far away you sit, the further you are, the lesser the difference it will appear to your eyes. The sharpness in the display picture makes a huge difference in between 720p and 1080p with trained eyes. That being sad, I'm clearly not a big fan of AA in general when it comes to gaming and would rather be at a higher res than blurring out the edges like a cheap whore. /shrug