Just did the upgrade - smooth and no problems with db after the upgrade, everything came over fine.
First impresions is that its much faster to load and apply settings. Clone and Heal Tool in the develop modul (non destructive) is really cool and then i am happy to see the Linear Gradient Tool that i have been missing
Another small thing is the "info" pane that is added when you browse files were you fast and clearly see what rating, categories etc you have set on a pic, as well as basic Exif info.
So far happy with the upgrade ($59).