I upgraded my laptop with IE 7. I have noticed some significant differences.
Firstly, the proxy.pac is now working perfectly. The problem that I had previously was that whenever I logon to my company VPN, the proxy.pac script failed to detect the IP address change. This caused the proxy.pac continue to use the old proxy settings. The IP address change could only detected after some time delay (longer than 5 minutes). This delay was annoying.
Secondly, the search function invoked by CTRL+F has been improved. The obvious change is that the search will now wrap around to the top of a document if the search reaches the bottom of the document. Also the search function invoked through Maxthon will not hang on certain web sites.