I've found George Ou to provide some good technical writing for Tech Republic.  He also shares that IE 7 is a "must have" upgrade and positive comments from a security perspective.

George Ou - Bottom line on IE7
http://blogs.techrepublic.com.com/Ou/?p=349

QUOTE: So what does IE7 really mean to individuals and companies?  If you're using IE6 as your primary browser, IE7 is a must have.  For IE6 users, IE7 will offer a huge improvement in the user interface though it is highly recommended that you follow the welcome tutorial to get acquainted with it.  The UI is much more streamlined and the traditional file-edit-view menu is always hidden though you can still make it show up by hitting the ALT key.  You will still have compatibility with IE-only webpages but the browser is also a lot more compatible with the web standards. Everyone one of my friends I've talked to has had a very positive experience with IE7 and we can thank Firefox for forcing Microsoft to deliver IE7 on Windows XP for free.

From a security standpoint, IE7 offers a huge improvement over IE6.  The two most recent zero-day exploits from last month for example only affected IE6 and not IE7 because the code auditing on IE7 was rigorous.  The ActiveX footprint in IE7 is about 90% smaller than IE6 because almost all of the ActiveX controls were completely disabled by default and only the most critical ActiveX controls for things like Media Player and Adobe Flash were kept on.  Even if you're running an alternative browser like Firefox, you're still going to want to get rid of IE6 by installing IE7 if you ever need to use IE for anything.