I read the previous thread regarding the Opera browser. However, i have been using the beta (Opera Next) version 12.11. I went to the following site:
<a href="http://html5test.com/index.html" rel="nofollow">http://html5test.com/index.html</a>
Out of a possible 500 score, here is how they rank, so far...
Current Browser Score Bonus
Maxthon 3.4.5 » 457 15
Chrome 23 » 448 13
Opera 12.10 » 419 9
Safari 6.0 » 378 8
Firefox 16 » 372 10
Internet Explorer 10 » 320 6
As you see, Chrome is up there, but Opera beats out Firefox. The only caveat being that Firefox may excel in the specs Roll20 requires where Opera does not. Not certain, however, the new Opera ranks much higher than the previous iteration. It might well be worth another look.