Just how do these betas stack up against each other? While nothing is set in stone, development has progressed so much on both browsers that what we see now is largely what we can expect for the future. With that in mind, InformationWork has put each browser head to head to see how they compare. They go over how well both browsers handle phishing attacks, the tabbed browsing improvements, RSS support (including external readers), built-in spell checking and even more. Suprisingly, in the phishing test, IE 7 beta beat FireFox by a significant margin.
How effective is the filter? In my tests, Firefox caught only one of four phishing sites tested; Internet Explorer 7 caught three. Here, at least, IE won, hands down.
If you haven't yet tried either of the new browsers, this is a great way to get a quick comparison between the two. It isn't a feature comparison, however, so don't expect a checklist. The article does mention that both browsers seem to be stable enough to use in everyday work.