No surprises there, Apple controls both Safari and OS X. Microsoft has done the same thing with Edge on Windows 10. Does that mean I use Safari on my Mac or Edge on my Windows 10 machine? No.
For me the killer feature would be some form of user profile, with segregated history and cookies.
I use Chrome because I can have two browser windows, one where I'm logged in to all my work tools and my work Gmail account, and another window where I look at Twitter and HN and I can have my personal Gmail account open.
I'll happily switch to Safari if they give me that. Chrome's general CPU usage aside, it performs especially terrible when using Google's very own products: video Hangouts (for work) and YouTube.
Google Hangouts in Chrome will set my Retina MBP on fire, but if I log in and join the Hangout in Safari, all is well again.
Yes, but when Mavericks launched the emphasis on power optimization features was new. There are also many performance compromises in Safari because of all the throttling.
The only exception is that I use Chrome when developing.