There is no WebGL and other HTML5 features that Chrome has. Also, not only there is no V8 JS Engine support, but I suspect that Apple's NitroJS engine won't work in Chrome because it probably uses UIWebView to render sites.

Well, WebGL doesn't work in Chrome on Android either.

True, though that may change soon. And other features like SPDY are already working on Android but presumably not in Chrome for iOS.

Correction: Another comment here says that Chrome is using its own networking stack on iOS, so SPDY is working. However, there are still other differences between Chrome and Safari WebKit, like the Audio API.

Yeah, no WebGL's a bummer. But at least it is close to the same engine.

Come on. It's close to the same engine in the same way Desktop Safari is close to the same engine in Desktop Chrome. You upgrade one, the other remains the same.