After some more use, there are still a few niggles i have. One, the new UI is taking a little getting used to, namely the page reload is now on the far right of the address bar, rather than with the back, forward and home buttons. Also, the link address that was normally in the bottom left is now next to the address bar, so long time reflexive viewers will now need to retrain your glance to the new areas.
Startup time would be fast, but for some reason, it's choking on my system, upon launch, tab headers appear and then the whole thing locks up for a min, doing whatever. So still has bugs.
In terms of developing web standards, it's almost on par with chrome now, so browsing CSS3 and HTML 5 pages are less likely to break. No Flash related issues so far either. Support for plugins will naturally be sketchy due to a new major version transition. A lot of the key and actively developed ones will still work.
The new tab management is kind of funky, i'm still not used to it yet, not to mention later versions will probably change the way it behaves, but so far so good. You can group large collections of tabs together into a single group and launch the group instead of each tab. So you can save a 'workspace' as it were with other apps instead of relying on the restore state feature. This i'm still experimenting with, so we'll see how it goes. After using chrome for so long and having those 8 most common used sites right infront of you in a new tab... little hard to tear away from the convenience.