High Sierra photo editing slow

My Photos is at present working as it should!!! Here is the pain I went through to get this working:

1. I backed up my drive to an external drive using Superduper! - This makes a bootable copy of my system in case something went wrong( I also back up to Time Machine and Backblaze but I wanted to be safe)
2. I did a clean install of 10.13.3 High Sierra - which included the following steps
   1. Created a bootable installation USB drive for 10.13.3 High Sierra
   2. Booted system to the above USB drive
   3. Erased my hard drive using disk utilities on bootable USB
   4. Installed High Seirra
   5. During install, 1 migrated all users, data and settings EXCEPT applications from backup I made in step 1. This means I will have to install all 3rd party apps manually.
3. Once Step 2 completed in total(about 7 hours later) I tried using Photos and it worked great! Yay!
4. The next thing I did was install back my missing apps one by one. After each app install I would restart and check Photos. The apps that installed and DID NOT affect Photos performance are as follows:
   1. Office 2016
   2. Pages
   3. Numbers
   4. Keynote
   5. Backblaze
   6. Chrome
   7. Firefox
   8. Parallells
   9. iMovie
   10. Steam
5. Dropbox however broke Photos. I installed Dropbox for Business, linked it back to my Dropbox folder, rebooted, logged back in and waited for a bit. Then I checked Photos and I was back to the lock up behavior described in my previous post Once I quit Dropbox and uninstalled it (threw it away out of the Applications folder) and restarted, Photos started working as it should.

I will keep checking Photos over the next week and post if it starts acting up again.

Hope that helps - Will send Apple feedback as well.