Performance
These days, browsers have to run more and more applications based on AJAX, which means that JavaScript performance has become a critical factor. Our tests show that Internet Explorer 8 performs far worse in this area than Safari 4, Opera 10, Firefox 3.1 and Chrome 1 and 2. The only test where IE8 comes out on top is the iBench XML benchmark.
Windows 7, 3.2GHz Core i7 965, 6GB DDR3/1600; milliseconds (shorter bars are better)
Windows 7, 3.2GHz Core i7 965, 6GB DDR3/1600; points (longer bars are better)
Windows 7, 3.2GHz Core i7 965, 6GB DDR3/1600; points (longer bars are better)
Windows 7, 3.2GHz Core i7 965, 6GB DDR3/1600; seconds (shorter bars are better)
But what do these results mean in practice? Many websites now use images with JavaScript Lightbox animation. IE8 takes more time to display these images than competing browsers, even using a 3.2GHz Core i7 processor. Other AJAX applications, including Google Maps, respond worse in IE8. This slower performance extends across the other tests, including the pure JavaScript Sunspider, Google V8 and Futuremark Peacekeeper benchmarks.
IE8's performance shortcomings may not be much of an issue on the fastest desktop systems, but they translate into a real problem on, say, an Atom-based netbook. For systems based on less powerful processors the only real option is to choose a different browser.
Conclusion
In Internet Explorer 8, users will find a much more robust Microsoft browser. A crashed tab or a faulty plug-in will not bring down the whole application.
Any problems with the new rendering engine results will depend on the websites visited by the user. But sooner or later users are bound to have to use the Compatibility button to solve problems loading certain pages.
The day-to-day impact of IE8's weak JavaScript performance may not be as drastic as the benchmarks suggest. But why Microsoft is so far behind in this area is difficult to understand, especially as the number of AJAX-based websites and web applications is growing steadily, along with their complexity.
Web Slices and Accelerators are very practical features. Since they are on by default in the browser, their use will spread quickly. However, IE8 ultimately offers nothing that users of Chrome, Firefox, Opera or Safari do not already enjoy, and so the loss of further market share is almost inevitable.
It's all well and good to ask if Microsoft has done enough but as I've been using IE since Netscape stopped being a serious contender (read: after V4.7) the way I look at it is that I need to ask if Microsoft's new opponents are doing enough to drag me away from IE. Safari has a pretty GUI, Firefox has its little addon toys and Chrome is viewed by Google fanatics as the latest and greatest which I guess explains its 1% market share.
I'm on IE8 and can't see any problems with it so I guess there is no compelling reason for me to change at this point in time. Still, all this comes down to taste and personal needs. One compelling reason why I will never use Chrome is that I am of the understanding that Google collects information from the browser to steer their advertising engine regardless of whether you want them to or not. IE8 can block all these sorts of hidden transmissions of information and for people that like browsing websites instead of billboards this is a comforting feature.