We've switched many of our work systems to it, as well as upgrading home systems. It has one "feature" that neither Chrome nor Firefox has that we found out by accident - on many sites, the page won't display until embedded advertising finishes loading. When one of the ad sites was having a problem, my users were complaining that sites like MSNBC would hang the browser -which it did on the other two and on IE7, but not IE8.
Other than that, it's remarkably faster than IE7 was. I give it a cautious thumbs up, so far.
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