I have been a loyal Firefox user since the beta days, and still see no need to "switch". I have had all said above browsers installed at once, but always kept going back to FF. Yes, I have seen the bugs here and there, FF crashing on occasion, etc, but it's the browser that has stayed constant in stability and expands with "add-ons" and "plug-ins", not that I use many anyway. It's the "feel" I get using FF.
Since Chrome, I would say that it is a slightly faster browser (compared to FF) in sheer speed in loading webpages. But, it's not so much that it should make you want to "switch" on that alone. FF has had a lot of years invested in its' browser. As new standards come along, and hardware acceleration, FF will be there to support it.
Also, I would say there is a "creepy" part of Chrome, but this is just me. Google is just becoming so huge, and wants to know everything about everyone, and every little thing you click, buy, etc. Not that I care anyway, but it's just that aspect that creeps me out a bit.
On a last note: This review just reiterates why I love Firefox and why I seem to always come back to it after trying a new version of Opera, Chrome, etc. It's kind of right in the middle of everything and comes out on top in some things and is always expanding.
I don't touch IE with a 10 foot pole, and haven't in a while. Unless it's working on someones computer where IE does them just fine (but will recommend FF), or those few ActiveX sites, that are once in a blue moon.