JFYI with jailbroken device you can enable the nitro in all apps, not just Safari.
Octane benchmark in Chrome with Nitrous jailbreak tweak: 4753
Octane benchmark in Safari: 4445
iPhone 5S 7.0.6
there's also an small tweak available which will make Chrome the default browser on iOS. (same as there's a tweak to make Google Maps default)
so if you do have a jailbroken phone, third party browser are actually better than Safari on iPhone and iPad