It seems that they both produce templates that are close to the Elizabeth Shown Mills Evidence Explained models, but both need some adjustments.
The question is now – when transferred to my website, which citations transfer across best? On my website I use The Next Generation of Genealogy Site-building (TNG) by Darrin Lythgoe.
To test this, I chose to compare a Vital registration State Level certificate, since this template in both programs matched the model
This is how the individual citation looks when created with RootsMagic
This is how the individual citation looks when created with Legacy
This is how the master source citation looks created with RootsMagic
This is how the master source citation looks created with Legacy
By changing my master source name to Death certificate, Victoria, Australia, and by adjusting the code in TNG to remove the Title and only show the Short Title (I found out how to do this at http://lythgoes.net/pipermail/tngusers2_lythgoes.net/2008-July/078410.html), the entries from RootsMagic then become closer to the models.