Everything just works so much better with 10.2 than 10.1. Though there are bugs here and there, for the most part it's very fast when compared to 10.1. Also now being able to use Quartz Extreme with a Radeon PCI makes it even better. Only problem that I noticed is that the dock pop-up animation is choppy, and seems to skip some frames. Quicktime movies get corrupted when anything transparent is placed in front of it. Last but not least in PandoCalendar, when I change the months or the year it doesn't always update it (99% of the time) unless I click on one of the date to bring up the window where you can enter notes.
With or without the Quartz Extreme over Radeon PCI, I still give this a 4. Maybe a 5 when Apple get the bug fixes (10.2.1) out in the coming weeks.