I always end up coming back to Safari for personal use. It seems to do the best job getting out of my way. I am annoyed by how Safari now handles browser extensions. I’d like them to take a page out of Orion’s book and support both Firefox and Chrome extensions. However, I generally have very few extensions, as they tend to slow things down, so this has been a relatively minor issue. The main things I’ve wanted extensions for in other browsers (like word lookup) have come out of the box in Safari (or Apple platforms as a whole) for quite a long time.
Using the 3 regularly, no, Firefox is not "10 times better than Safari". Though, yes, Chrome(ium) is a ressource hog.