The search bar in Firefox always assumes you're attempting to visit a URL if you type two words separated by a dot. It's incredibly frustrating trying to search things like "table.sort" and being redirected to a URL that doesn't resolve to anything and will almost certainly not for a while. Chrome doesn't have the same behavior (it ships with a list of valid TLDs). I get that you can work around it easily by typing a space, but the habit is ingrained for me due to switching from Chrome and this alone makes me want to switch back, if not for the desire for Mozilla to succeed. There is a bug for this issue[0] which has been open for 5 years.
For FF mobile the UI is less convenient than Brave. In Brave the icons for adding a new tab and switching tabs are at the bottom of the screen, while in FF they're in a menu at the top. Because I use my phone in portrait mode I have to reach my thumb up to the menu every time to create or switch tabs. It's really tiresome and I use Brave instead due to this. Also, the URL bar on mobile FF has the 'X', but its behavior is completely different from Brave. It closes the bar entirely rather than clearing it. I also get that it's a thing to get used to after switching, but why not just delegate cancellation to the Android back button? (Could it be due to iOS?)
One Firefox option I love but don't see used much is the optional search bar you can add next to the url bar. I MUCH prefer to use that for searching for two main reasons:
1. It always "just works". I've run into problems with both Chrome and Firefox getting confused by a search term I entered into the URL bar.
2. The search string persists even after clicking on results. This is particularly helpful when I'm having trouble finding a good result and want to make a slight change to my previous search string, or I want to remember exactly which search term brought up a specific result.
For FF mobile the UI is less convenient than Brave. In Brave the icons for adding a new tab and switching tabs are at the bottom of the screen, while in FF they're in a menu at the top. Because I use my phone in portrait mode I have to reach my thumb up to the menu every time to create or switch tabs. It's really tiresome and I use Brave instead due to this. Also, the URL bar on mobile FF has the 'X', but its behavior is completely different from Brave. It closes the bar entirely rather than clearing it. I also get that it's a thing to get used to after switching, but why not just delegate cancellation to the Android back button? (Could it be due to iOS?)
[0] https://bugzilla.mozilla.org/show_bug.cgi?id=1080682