You can really notice how well it works when developing sites. Also, it shows and works sites better like Grooveshark and more than Firefox 3.6 did. Also, response, stability, and CSS is the biggest improvement I see using it on Ubuntu. I usually had to click links twice or more to get it to work on Ubuntu 3.6 for some reason under localhost and browsing the web. Also, pages load just as fast as Chrome. As for freezing, my YouTube videos and others don't grey out anymore like they did with 3.6.
It makes the best default browser for me on Ubuntu One great reason like before is that you know majority or all Firefox users will be using it and you can finally do things with websites you couldn't while it was in beta. Everything I do now with CSS now shows great on Firefox, Safari, Chrome, and even Opera now. It's only gonna get better with all advancing browsers pushing out updates on a quicker cycle.
This may be true for Ubuntu but browsers run very differently on different operating systems. Some of the bugs you had in 3.6 were not present on the Windows versions so maybe we need insight from more people using Windows. The best example is Safari. It only runs well on a Mac and is absolutely horrible on Windows.
Edited by hab, 23 March 2011 - 10:33 PM.