Firefox vs Opera

I decided to share my impressions of choosing a browser and ask for advice.

So I like Fox
! displaying links ;-)
! Of course, modularity (extensions) - for example, the WebDeveloperTools that I use - there is no such thing in Opera, but I would like to
! correct work with services from Google (Opera used to have troubles at one time with displaying Gmail, for example, and I generally am silent about Google Docs) I

like Opera
usability - it's something
...! access to the top ten and favorites when stepping into the address bar
...! built-in mailer, for example, picking up mail from the same Gmail
...! reading feeds (short feed descriptions) in the same browser
...! the ability to easily configure search plugins - you just get into the search bar in the place you need and click on the right button “Create Search” (for example, separately from Google pictures, Yandex dictionaries, etc. - it doesn’t work only with SearchMash)
...! of course speed

I don’t like the impossibility of setting up search plugins in Fox the way I want - if you know how to do it quickly - please share ...

I also don’t like the eatable memory volume in Fox

And of course, the lack of those convenient amenities that Opera has in

Opera I don’t like the fact that they don’t use the idea with widgets to the fullest - there isn’t such a set of features as the Fox extensions \ although I probably don’t know much \

Do you know how to combine all the goodies “in one bottle” and who chose what for why?