I made the switch
After working with Maxthon as an Internet Explorer replacement (which it isn't, its merely a shell for IE) I found more and more pop-ups being able to get around the Maxthon blocker and the Internet Explorer problems were still inherent in the system. I spent over 6 hours last week removing the latest version of CoolWebSearch and its cohorts from a coworker's PC which got installed because of the way Internet Explorer deals with pop-ups and exe installs. I've been a long time hold out for IE, but I've had it. I've switched to Firefox.
I'll report back and let you know what I think about Mozilla/Firefox.
As for spyware and the like, I've found a new (though commercial) application which did a very good job of removing the problems on that coworker's PC and I therefore now recommend Spyware Sweeper. It came with a free trial, which actually removed the spyware and found more than AdAware and others combined. I still recommend HijackThis for basic investigation, but Spyware Sweeper did a fine job. Be very careful installing any other 'spyware removing' software, as some are designed by spyware publishers themselves.