For me, Phoenix/Firebird/Firefox was a noticeable step up from IE, and Chrome was a noticeable step up from Firefox. Chrome did especially well relative to Firefox when I had a lot of tabs, and for JS-heavy sites.
I bounced back and forth several times:
* I tried it for a month in January 2010, and went back to Firefox because Chrome was slower and less stable: https://www.jefftk.com/p/google-chrome
* I tried it for ~6m in 2011, and switched back to Firefox because I missed side tabs: https://www.jefftk.com/p/side-tabs
* In early 2012 I switched back to Chrome, despite the lack of side tabs (which I still miss dearly) because it was enough more performant.
(Disclosure: I work for Google)
