It's definitely faster. But the reason to upgrade is the new drop down window shade that allows you to quickly switch between tabs. Pull it down like the notification bar, and you can slide between tabs or close them altogether. It also gives you quick access to the Android notification bar without having to go back to the home page.
I found this feature by accident -- I did not see it listed on the Dolphin homepage. The only small drawback is that if you try to hit a link at the very top of the page, it will activate the shade. Zooming in gets around that.
Just made my default browser even better.