I used to use firefox all the time, and safari only for downloading youtube. I eventually (to be more mac-based) ditched firefox.
I liked how stable safari is, how fast it is, and I made peace with the menus needing to be individually clicked on (I have folders in my bookmarks toolbar, which have lists of bookmarks each with a specific class, ie: "Local", "Resources", "Sites", "Torrents", "wallpapers", "Banking")
I would (in firefox) click one, and see the list, then move the cursor over to the next folder, and it would open automatically. In Safari, I have to click each folder manually. It annoyed me at first, but it is no problem now.
The only firefox plugins I used were themes, and the youtube downloader, which never seemed to work, but safari does.
So far I use almost all apple apps except iPhoto. I never did like it.