The best way to update CRM forms

Hi all,

I am looking for the best method to move from an older CRM form to a newly updated form. 

I know about the "Merge" button - but is that the best way? If I Merge the two forms, then the older form will be deactivated (I know that I can reactivate it if needed.)

Is it better just to manually move everything over to the new form so that the layout is the same? 

We are moving from 2011 forms to 2016 forms.