I have both Chrome and Firefox installed on my Mac. I take turns switching between them and Safari. I don't want the "there can be only one" browser limitation to ever happen again. They're all free, and they're trying to implement open standards. Let's spend a little time with each of them.
Thing is I like to customize some things and sometimes I do that by writing an extension and adding such and such so using other browsers at the same time becomes harder.
I use chrome now because it starts up fast and I have all the things I like, if firefox started up faster and had similar window freedom (last I checked linux wasn't as lucky as windows) I would switch back. The update thing was just a nitpick that if I could see changes happening over time rather than one huge update it would entice me back.
Totally agree on using multiple browsers. (Plus ever since Google started enforcing that "one gmail session open per browser" rule I've been forced to use both Firefox and Chrome when I want my personal and work emails open.) I think my time with Chrome also helps me look past Firefox's deficiencies, if only because I'm not constantly frustrated with them.
