Good and not quite as good...
I can affirm what others have said (faster iphoto/spotlight, louder volume). One oddity that presented itself is that the OS no longer saw any of my external Firewire drives. It saw my USB drive find but my 3 Firewires were MIA, not even showing up in disk utility. Repairing permissions and restarting didn't fix it either. So I restarted one more time after disconnecting everything from the iMac except ethernet, power (duh) and keyboard/mouse. Then I added the drives one by one after booting was completed and they all work properly. A little odd, but I'm just glad they're back.