- Recently closed tabs (AFAIK "Undo close tab" currently fakes it by not actually closing the tab until the "Undo close tab" popup has disappeared)
- The Firefox share target that actually gave you a choice whether you'd like to open the page in Firefox directly, merely bookmark it or use Sync to send it to some other Firefox instance without having to actually open the page in Firefox first
- Add-on support that isn't limited to a few blessed "Recommended extensions"
- viewing local HTML files is not possible (although admittedly Google hasn't helped there, either, by vastly complicating file system access in recent Android versions, and their purported replacement method is absolutely unsuitable for HTML files that depend on additional resources such as images, styles, scripts, other HTML files etc., but in the end it was still Mozilla's decision to disallow it completely right now)
- about:config
- View source
- bfcache is broken
- cannot force-refresh a page
- the tab import from the previous versions drops all the session history of those tabs, i.e. it only imports the currently viewed page, but you can no longer go back or forward
- Recently closed tabs (AFAIK "Undo close tab" currently fakes it by not actually closing the tab until the "Undo close tab" popup has disappeared)
- The Firefox share target that actually gave you a choice whether you'd like to open the page in Firefox directly, merely bookmark it or use Sync to send it to some other Firefox instance without having to actually open the page in Firefox first
- Add-on support that isn't limited to a few blessed "Recommended extensions"
- viewing local HTML files is not possible (although admittedly Google hasn't helped there, either, by vastly complicating file system access in recent Android versions, and their purported replacement method is absolutely unsuitable for HTML files that depend on additional resources such as images, styles, scripts, other HTML files etc., but in the end it was still Mozilla's decision to disallow it completely right now)
- about:config
- View source
- bfcache is broken
- cannot force-refresh a page
- the tab import from the previous versions drops all the session history of those tabs, i.e. it only imports the currently viewed page, but you can no longer go back or forward