I have LR5 standalone. I am considering upgrading to LR6 CC. If I download LR6 CC on a trial basis and then decide to stay with LR5, will my LR5 and catalogues still work? If not, can I still upgrade upgrade to the LR6 standalone version?
You can do either. The two releases will co-exist side-by-side, and your LR5 catalog won't be touched by Lightroom 6/CC. You can uninstall the trial if you don't want to keep it afterwards.
Many thanks, looking forward to trying the new version.