After installing the beta, the first thing that'll hit you once you load the beta up is just how much cleaner and better-looking Internet Explorer 9's interface is. Gone is the barrage of toolbars, randomly placed icons, glaring colours; what you get now is a nice minimalistic, monochrome interface that fits surprisingly well into Windows 7.
While the interface sure is a major improvement in the looks department, it makes some curious choices I don't really understand. Chief among these is the rather odd placement of the address bar. Not only does placing the address bar on the tab bar reduce the already limited space available for tabs, it also makes it impossible to glance at your url.
Tabs quickly become unreadable - have more than 4 tabs open, and you'll be unable to read the page titles. Other browsers also suffer from this problem, but at least other browsers don't waste 1/3 tab space on the address bar. Tab overflow is available in IE9 (unlike in some other browsers - yes, I'm looking at you, Chrome), and takes the form of arrows on either end of the tab bar.
The new tab page is an exact copy of what we already know from Opera and Chrome; in other words, a list of most often visited sites. It has the additional nice but useless touch of a usage indicator (i.e., how often you open the page in question). Sadly, the new tab page does not use miniatures - it just uses favicons and the name of the site.
Notifications pop up from the bottom in pretty much the same way other browsers have been doing for ages. Another oddity - which I'm ascribing to the software's unfinished state - is that the
bookmarks favourites bar still uses the old-fashioned hideous gradient from IE7 and 8, which looks remarkably out of place in IE9. Also weird is the total lack of animations in the interface; if you close a tab, there's no subtle gliding animations of the tabs rearranging as Chrome has, making it all kind of jarring.
There is one rendering issue which I'd like to address, and that's fonts. As a Windows user, I've come to expect crystal-clear ClearType fonts, but for some reason, Internet Explorer 9 gives me slightly fuzzy fonts on some websites, fonts which reminded me of how Mac OS X renders its fonts. I'm assuming this is caused by the new feature in which font-rendering is hardware-accelerated, and lo and behold, switching to compatibility view returns fonts to their normal state.
IE9 also integrates very well with Windows 7, making optimal use of Jump Lists and the taskbar. For instance, you can pin any website to Windows 7's taskbar, which has already become one of my favourite features in IE9. The website's icon will appear in the top left of the window, functioning as a home button, while another nice touch is that the back and forward buttons will change colour to adapt to the pinned you're currently viewing. This is very handy for more application-like websites such as Facebook and Gmail.
More technically included web people will have to weigh in on the standards support stuff, and impatient people will have to look at the performance stuff, but the interface of IE9 is an improvement over IE7 and 8 which introduces a few curious choices. I don't think it'll convince any of us hardcore users to switch back (they can pry Chrome from my cold dead hands), but it will surely leave a positive impression among people with no strong inclination one way or the other.