I've been running Firefox full time on all my computers for a few months now. It's been really good. I've tried to switch away from Chrome in the past, but I've always had to come back due to performance issues or incompatibility with something. But it's basically 95% on par with Chrome now (missing a few things like syncing search engines, etc)
Meaning the search engines that appear at the bottom of the URL bar (respectively the separate search bar in case) and of course also the default search engine that is used when you load something that isn't an URL in the URL bar.