Yes, it is a bit complex with all the settings, but it is for the benefit of a better, more flexible gallery. I hope we can make the configuration easier to change in the future.
You don't need to re-install everything, but you may need to redo your theme customization since you have an older version where user config changes were not kept in a separate file.
viewtopic.php?t=4160
There are many benefits and improvements in every release. Many may not be important to you, but some may have advantages. All you can do really is follow the updatelog:
viewtopic.php?t=3241
... check our main demo to see if there are any new features in the examples that you like:
www.photo.gallery/soda/