Not that great

The only reason I've given IE9 any stars is for the developer console which you can bring up by hitting F12. Its really handy when you're coding in CSS3 and HTML5 as you can simulate older browsers IE7 and 8 to see how your progressive enhancement techniques are working.

In all other areas however, IE9 is slow and clunky. It's particularly frustrating for web designers who find themselves having to check their own code in order to get around IE9s (and its predecessors) gross inadequacies.

In short IE9 has everything you'd expect from a Microsoft product and I would therefore never recommend using it to anyone. In fact I would actively discourage its us and extol the virtues of Google Chrome instead for those looking for a fast, clutter and stress free web-browsing experience.