Recs.
Updated
SpecsUpdate
Pros
Pro Ethical and pragmatic company mission
The Mozilla Manifesto outlines the company's mission and principles. Paraphrasing, they want the Internet to be a free and open resource, and to enable individuals to get the best use of that resource. They do this by creating open source software to which anyone may contribute, so long as such contributions fit with their principles (both ethical and technical).
Pro Android version allows installation of addons
Unlike other browsers, Mozilla uses almost the same codebase as with the desktop version so extensions work as-is without code modifications - something other browsers cannot do due to their breaking and sometimes unrelated code branches to the mainline desktop branch.
Pro Uses less resources
Firefox 57 (Quantum) and newer uses less resources than ever. It is proven with benchmark done by AppleInsider.
Cons
Con No scrollbar marks when searching a page
When you search in a website (Ctrl + F) there are no marks appearing in the right scrollbar. All Chromium based browsers have this feature.
Con Can't play flash videos
Due to security concerns, Firefox does not include Flash support by default.
Con Mozilla once partnered with George Soros to fight misinformation
Mozilla once partnered with George Soros to fight misinformation.
Recommendations
Comments
Flagged Pros + Cons
Pro Reader View
Reader View in Firefox allows users to read an article without any distractions by removing ads, unrelated elements and other distractive objects (similar to Microsoft Edge's Reading Mode and Safari's reader mode).
Con Multi Profile is not user friendly
Multi profile requires commandline -no remote to use and open about:profiles to create manually (on Chrome, you can instantly create them on right top user button).