Unless Google has done a lot of work with WebKit then it is going to be a pretty awful experience. You only have to compare the native Google Maps with the web version to know that "touch" is poorly handled by browsers. It is an order of magnitude slower that apps which like it or not are the benchmark Google needs to compete against.
Chrome on Android handles it just fine, though I'm not sure what specifically you're referring to (Chrome on iOS is just a wrapper around UIWebView so it doesn't really count).
Also, on iOS there is a ~300ms delay between taps and the "click" event (see for example https://github.com/ftlabs/fastclick) which is not present on non-iOS browsers. Perhaps that could explain why it appears so slow for you?
its not even a fair comparison they both use different javascript engines. I won't comment on Apple's treatment with javascript on their mobile browser.
