Hi Robert,
When was the last time you went to Store and made sure you are receiving automatic updates for your apps?
I ask, because recently I needed to repair my Photo App as it would not even open.
After resolving the issue there I discovered it would not download from the Store, but then resolved that issue to - I've published an Article about that here recently. However, what I noticed was there was a new update for the Photos app and in my personal opinion it greatly improve it and I've not noticed any particular tardiness in its running.
It'd be worth visiting Store and checking you have no pending updates for the Photos app before changing to some other medium for working with your images.