>What html5 features would like to use that Safari/Chrome don't do?

Good comparison site : http://html5test.com/results/desktop.html
Interestingly Maxthon comes out top for the desktop, Opera for tablets.

TBH I don't see much point in developers debating which is the best browser - that's usually the choice of the user and you have to live with it......

Like it or not IE seems to be predominant in North America (and oddly China ?) ; Chrome in Europe:
http://en.wikipedia.org/wiki/File:Countries_by_most_used_web_browser.svg#filehistory