I've been using FireFox again instead of Chrome for all my web development for the last two weeks.
Here's what I've liked, and here's what I haven't.
I'm flabberghasted that Firefox don't make more of a thing about Sync. Once you've got sync setup on more than one computer (which is a bit fiddly, granted), you get this new option in your history:
Lets say you use one computer for work, and one at home, and you need to access one tab that was left open on the other computer. When I've used Chrome previously, I had to hope I remembered it was in the history in a method that I could access (which never really worked for me properly anyway).
With Firefox, I can simply select the choice in this menu, and I'll get a list of all the tabs open on all my computers, from which I can fetch the tab trivially.
What's more, I even have access to this tab from my iPhone if I want to with this app:
So if I'm looking at an address for somewhere, and I forget to write it down, even after I'm walking down the street, I can fetch that exact tab with the info I need, without much fuss.
Even as Chrome grows in popularity, I really like that Firefox exists - there's always a nagging doubt that whenever you use Google Chrome, (or indeed Chromium if you want the bookmark and history syncing) you're doing so with the understanding that you're happy to have your kidneys harvested by Google. Many of the ideas from the Mozilla tend to come across as more respectful of one's privacy, or as designed to help create a healthier web, rather than one that merely happens to be aligned with here Apple or Google are heading right now.
This Firefox plugin, that shows you how you're being tracked online is a good example of how the culture among developers on Firefox is arguably tilted in favour of the user than on Chrome. Also, the idea of an open app store, or their recent take on open mobile computing, with BootToGecko are fundamentally more attractive to someone interested in an open web than the ecosystems being cultivated by Apple and Google.
When I first started using Firefox, I spent some time looking for an equivalent to the Better History plugin on Chrome, that made it much easier to find pages you used before. When I asked Dees about about this, he suggested I try just using the (sigh) awesome bar instead, to see if I really did miss it.
A couple of weeks later, I'm a convert, it's uncannily good.
If your platform has a plugin like this on it, then I'm automatically a fan:
Regular, visible improvements in the browsing experience
Most importantly, there's visible progress with each iteration of the 6 week release cycle, with gaps in the experience being plugged each step of the way. The importer from Chrome is a great example of this now, although inexplicably Mozilla totally failed to mention it on their main blog post about the latest release.
Firefox is still noticeably slower than Chrome, and while it's a huge improvement on before, I still feel it struggling to keep up with me after using Chrome.
Disjointed Web Development
I've found myself having to resort to using both Firebug and the native web inspector to be effective when using Firefox since switching.
When doing front end work with Firefox, its own web inspector has an annoying habit of converting your colors to RGB values whether you like it or not, which gets pretty boring to convert to hex if you have stylesheets using the more common notation.
As a result I ended up falling back to Firebug, which overlaps massively with Firefox's own new tools, and using the two to get a single job done is much more fiddly than just using Chrome's web own developer tools.
That said, between the two tools, everything you could want to do in Chrome you can do in Firefox - it's just a shame it feels so disjointed at present.
While the experience of using Firefox as a web developer has a fair few wrinkles, it seems to be getting better so fast that it's worth riding them out. For a while, the cost of using an app that reflects many of the ideals of openness and respect for user's rights that Mozilla talk about has been a inferior user experience (well, from my point of view at least…) to that of Chrome or Safari. This cost is rapidly reducing, to the point where it's close to disappearing - for me this is great news for the web. I'd happily recommend trying out Firefox for a couple of weeks yourself to see how you get in - I think you'll be impressed like I was.