I'm a new user of RootsMagic 7. I have family trees on both Ancestry and MyHeritage, and they are a little different in some respects. Can I pull a GEDCOM from each one and merge them somehow on RootsMagic 7?
Firstly my answer needs to be a little theoretical as I am not a user of RM7.
I believe the new to RM7 feature 'Compare Files' may be of some use to you. If you pull both gedcoms into RM7 databases and then compare them the new feature will be of some help in resolving the differences. Rootsmagic also has a Smartmerge feature which may help resolve some of these differences automatically, either way these are the two terms to search for in the help file.
I am slightly guarded in my reply as I believe RM still has a lot to do here to assist users merge files and avoid duplication. If you watch the Whats new in Rootsmacic 7 video you will see the Compare Files feature explained around the 30 minute mark where Bruce states there is still much which is to be achieved in the future.