From my meagre experience, the biggest problem with IE6 and 7 (and to some extent 8) is incorrect layout. Beyond very simple pages, it becomes almost impossibl

From my meagre experience, the biggest problem with IE6 and 7 (and to some extent 8) is incorrect layout. Beyond very simple pages, it becomes almost impossible to get the same page to look even remotely the same on both IE6 and modern browsers. One solution I've seen used is to disable styles entirely on IE6 (and suggest Chrome Frame) and deal with IE7/8 quirks only.