so I wanted to see how well supported are HTML features by each one of them.
One year ago this was a difficult task as there were not so many tools but right now this job is easier.
As my "daily" browsers are Firefox 3.6.x and Internet Explorer 8 here is the level of support for HTML5 each has (according to http://html5test.com)
Firefox 3.6.7 - Score 139
Internet Explorer 8 - Score 27
So, next time you find yourself cursing Internet Explorer remember its score :)