I am trying to understand Gantry 5 in order to use the newest Rockettheme Templates for Joomla. However, the use of the Home and Default pages has thrown me off a bit. I decided to publish a solution I found to a problem no one else on the forums seems to have had yet: trying to mesh the menu home with the template home. The first technique I finally figured out was that under the home template, you have to be sure to assign it to the home form the main menu, too. Why? I don't know. That's under assignments.
I monkeyed around with a lot of other settings before I figured out the next one, though. I was getting featured content to show up on the "home" page when I clicked on "home," but the content would not show up on the / main page. I tried all kinds of changes in the template. I eventually went to the main menu, clicked on Home, then checked "Default Page" to Yes. This was never an issue with Gantry 4, though I didn't tend to use separate template assignments with it.
Anyhow, if you run into similar problems getting your home menu to line up with the template home, those are two simple fixes that took me too much time to figure out so that you can look like a wizard right away. Now I just have to hope all the other settings I played around with weren't the wrong ones to change.