I can tell you from my own personal, anecdotal experience, it's one of those things as soon as someone knows about (and fully understands) they typically become Chrome users everywhere because of it. I found this to be the case for our Apps domain users at work and even friends & family who just have personal Google accounts and maybe even use iPhones, etc. It's powerful to show someone that your history, bookmarks, and even open tabs across devices stay in sync. I find that if one isn't "creeped out" by that, they usually think it's extremely convenient.
I certainly do; its a pretty significant convenience if you are a device-hopper.
The tables might have turned, but Microsoft keeping competition up is necessary to maintain a healthy ecosystem.
#1 Spartan gets rid of all the legacy back-compatibility code that was holding them back.
#2 They added very interesting features that I haven't seen in other browsers (i.e colaboration)
Every browser pretty much presents webpages correctly according to modern CSS standards.
Every browser is fast enough that the difference is negligible
Not many people use any major add-on features of browsers, except like adblocker and stuff like that.
I really don't understand why this is an area that's worth competing in anymore, except providing an browser for your mobile ecosystem (chrome for android, spartan for windows phone, safari for apple, whatever). Webpages are still needed but apps are sweeping the field and providing better UX for the webpages that people use the most.
And downvote me as you might but firefox days are sadly counted