not very pleased
well, having used IE 9beta for about 2 days.
it doesnt seem that there has been a real improvement of the browser itself, i feel just that it sucks resources from other cores. having it to draw from GPU also feels to me as a false speed up, not a real code and subroutines optimization...
moveable and dockable tabs are nice, allows you to pop-in some of those you dont want to open in a new window. keeps taskbar organized.
addons and download managing has also had a nice improvement, liked the way it is now.
last but not least, i found out some important flaws.
it seems to brawl with some security add-ons or password textplaces like in netbanking. I simply cannot login to my banks network using ie9. (maybe HTML5 conflinct)?
also im having problems with the way it is drawing general items on the screen, name it tables (like credit card statement online) or social network scrap pages. (orkut.com)
if anyone is having some issues like those, please report.
hope this is helpful.