I tried switching from Chrome (actually I use chromium) to Firefox, but I switched back after one day. I didn't have any problems with any websites in Firefox, but the user interface of Firefox is just lightyears behind Chrome. What really was a deal breaker for me is how Firefox handles tabs, it's just not usable if you open more than 15 tabs in total because you can't move more than one tab at a time.

When I look online for say a RAM upgrade for my computer, I open a few tabs with online shops, then I open a new tab for each product, now there are ~40 tabs open and I want to move half of them to the beginning of the tab bar or to a new window. In chrome I press shift, select multiple tabs and move them, In Firefox I have to drag each tab to it's new position one after another.

In about:config there's a flag to enable tab multiselect, but you still can't move more than one tab at a time.

There's a few more minor issues like this and a 5 year old unfixed bug with tiling window managers in Firefox. With Firefox I just spend more time fighting the browser than browsing the web.