I had to call Sony's tech support after I bought mine to be informed that 60" screens may be a tad too large for the video processor.
Did Sony
really tell you that? It's just the screen size?
It has nothing to do with screen size and everything to do with the size of the pixel matrix. The laptop screen is 1440x900 and naturally the video card will be chosen solely on that need to meet price points. A 60" anything is more than likely 1920x1080. If you could buy a large 1280x720, 720p display the video card would actually have more processing power. Ultimately if the laptop was running a 1080p equivalent screen, for PC that is 1920x1200, there would not be a problem.... within reason... just because a PC supports that scan rate does not mean the video card has the horsepower to satisfy all users and the needs of their individual applications.