Chrome has been my primary browser for years, and I still feel a tad more familiar with its developer tools. Lately on my work machine, it's gotten sloooooow-- I thought the lagging in typing and general responsiveness was the whole system, but mercifully no - just chrome. The timing corresponds with upgrading my OSX to El Capitan, and a few other changes related to my employer being purchased by AOL. (I tried resetting it back to manufacturer settings, next step is to uninstall and reinstall I guess.) Of course, I'm kind of nervous there's could be some kind of malware involved, but we'll see.
Anyway, I've been using Safari - I've been told its a lot more CPU-efficient than Chrome these days, and in practice it's not so bad. My biggest gripe is this: most of they key mappings are smilier between Chrome and Safari but Chrome has a brilliant shift-cmd-t to retrieve an inadvertently closed tab. Bizarrely, Safari tucks similar functionality under the "History" menu, and deals with only on a window level, not tabs- very retrograde of them, IMO.
(FOLLOWUP: one other difference is how in Safari shift-click on a link means "download this right away". I guess it's more arguable if this is a reasonable thing to do. It certainly seems weird to send a webpage to Downloads/ when I just meant to open it in a new window... and since cmd-click means "open in a new tab", Safari seems doubly confused about the purpose of windows in the modern web browser.)