SuperPreview - IE Plugin - for Microsoft Expression Web

I haven't had a chance to mess with this yet, but thought it would be of interest to many of you. Give it a try and comment back here with your experience.

Excerpt from the Expression Web Team Blog.
SuperPreview shows your web pages rendered in IE6 and either IE7 or IE8, depending on which version you have installed on your machine. You can view the pages side by side or as an onion-skin overlay and use rulers, guides and zoom/pan tools to precisely identify differences in layout. You can even compare your page comp to how the targeted browsers render the page.

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