I too recently tried to switch back from Chrome to Firefox, but gave up. Lots of tabs highlighted the single process model. I love Certificate Patrol. Ctrl-W closes tabs with Flash just fine in Chrome, but required a click outside of Flash first in Firefox. And while Chrome went it alone with Pepper, at least they did something to really isolate and contain Flash. The final straw though was wanting my vertical space back - Chrome's tabs in the title bar is excellent at that. I eventually discovered that you can't do it with Firefox on Linux, and the relevant tickets were full of nasty comments about how Firefox should never do that. Oh well.
I originally switched from Firefox to Chrome because of some web code I was developing where I accidentally made the server send unlimited data (it was supposed to send one line of status information every 15 seconds - I forgot the sleep). Firefox's single process model resulted in a hung browser while Chrome let me find the cause.
The "temporarily hung interface" is definitively one of the worst things about Firefox. Fortunately they recently set up a project dedicated to fix it, next releases will probably behave much better. A few links for those interested
Vertical space on linux? That's simply not true. Exhibit 1: The default firefox and chromium running on my linux (ubuntu, i3wm). http://i.imgur.com/paE173H.png . 6 pixels by default in favour of firefox.
The real problem though is chrome's interface really is completely inflexible. I like a thinner browser than either of those. Hence, my firefox setup: http://i.imgur.com/XAyc8Tu.png .. 17 pixels more space than chrome can be gained easily (firefox with only the extension 'pentadactyl'). And further more, since firefox's appearence is all just XUL it can be styled to be as thin or thick as I like.
So yeah, firefox you can change the ui to be vertically thin. It's simply impossible to do that with chrome.
When I start up Firefox on Ubuntu running Gnome 3.6 classic or whatever they call it, I got the traditional firefox and definitely no tabs in the title bar, a bunch of vertical space used for the menus, address field and search field and the list goes on. I was able to customize the bars in order to move everything onto one line but couldn't make it the same line as the menu, and could only find bugzilla entries about not being able to move tabs to the title bar on Linux.
I originally switched from Firefox to Chrome because of some web code I was developing where I accidentally made the server send unlimited data (it was supposed to send one line of status information every 15 seconds - I forgot the sleep). Firefox's single process model resulted in a hung browser while Chrome let me find the cause.