Over on the Six Generations blog, genealogist Stewart Blandón Traiman has a very in-depth article up on the problems with synchronizing your data between your offline/personal software (in this case RootsMagic) and online services (in this case, Ancestry.com), and I should note it’s not inherently a RootsMagic or Ancestry problem, because it could apply to other genealogy programs and online genealogy services.
Here in 2024, and for the last several years, it’s been relatively easy to synchronize your data between, in this instance, Ancestry and RootsMagic, using RootsMagic’s TreeShare functionality (which has been around for many years). The entries are added to your tree and copies of the documents/photos are downloaded, all without your needing to annually enter everything.
As Stewart mentions though, this comes with a lot of problems, with source citations and how they may go against the standards being the first issue (especially when Ancestry.com is listed at the start of the citation), and the problems with editing or removing those citations in favor of another citation.
Another problem is how location data is handled, and how images are handled (Ancestry.com’s naming scheme versus your own personal scheme which most likely has more information). All of this can lead to a lot of problems down the road, particularly if you don’t pay attention.
If you regularly sync your online and offline trees, or are considering it, check out Stewart’s post and the solution he is using:
https://sixgen.org/why-i-dont-sync-rootsmagic-with-ancestry-anymore/
I know the pain – I have family trees on about half-a-dozen online sites – Ancestry, MyHeritage, FamilySearch, plus three websites running The Next Generation of Genealogy Sitebuilding. I do all of my main research offline, with multiple databases, and when I need to backup or sync those or import data with online trees, I duplicate the offline database and am careful about importing data.