In the previous version of Firefox Sync I could use different settings per browser install for the same sync account to determine what was included. For example, my home desktop and my personal laptop would sync bookmarks, preferences, and add-ons but my work laptop syncs only bookmarks and preferences, not add-ons. In the new version even the sync configuration appears to sync which means I cannot use different sync settings on each machine. Very annoying and this means I cannot use sync with my work machine (there are add-ons I would not want on my work machine).