I first experienced Internet Explorer 8 on a Vista machine. 

My main memory of the experience was that it somehow got stuck on the personalise-IE8 screen every time I started the application. It would not accept the settings that I selected and just kept requesting them over and over again. 

This setup screen would open every time I started IE8 and try though I may, I could not find a solution. It didn't really matter though. Firefox was my default browser and I was also using Opera.  

Apart from the fact that IE8 integrates nicely Windows Live (the Microsoft Cloud), I have not been motivated to use it. It is still Internet Explorer and still has the same old silly pop-up messages. My favourite must be the "... do you want to see the insecure items" when you get into a secure site. 

As for speed of browsing, IE8 is still slower than Opera and Google Chrome. Using my 4 Mip ADSL, Opera and Chrome always load up faster. Opera is much faster. 

So the only real reason for using it is when a Site will not work on any of the other available browsers. Usually I discover that the site simply doesn't work at all. Chrome does have a few problems that prevents some functions on some sites from working as intended. 

By the way, the new version of Opera has a much more Windows 7 feel than the Microsoft effort. Move your mouse over the open tabs and a full thumbnail of what lies underneath displays. IE8 doesn't do that. 

Microsoft have managed a superb effort with Windows 7 and Office 2010 (still in Beta). IE8 doesn't quite make the grade.