And I'm back on Firefox. I remembered why I switched over.
Primarily: Forms don't work properly on a couple forums I frequent. the submit button does nothing in one, and copy/paste doesn't work in the other.
But there are a few more minor niggles, such as not being able to quickly reopen a tab I had just closed accidentally (which would be fine except when I had opened a bunch at the same time and can't remember which one I closed.
Overall there's nothing fundamental as to why I prefer Firefox, just that Internet Explorer needs some improvements that seem very likely to be in Spartan (especially with a better plugin system to pick up the slack).
Spartan should fix my problems, and then I'll use it as default.
In Firefox's spell check you can add words that are not in the dictionary.
One thing I hope Spartan has/gets is the ability to pin tabs like Chrome. I still prefer IE to Chrome, but pinning tabs is good protection against accidental closing, and they're loaded automatically when the browser opens.
I'd need to know more about it before I can make a decision.
I for one will not be switching from a FF browser due to the settings, all the links and passwords stored as they are portable across OS's.
Based on the hype, I'll switch to Spartan as soon as we see it, then if, in reality, it sucks I'll switch right back to Firefox.