elementary
Hide tab bar in full-screen.
The tab bar (aka "notebook") takes up a fairly thick band across the top of the window while Terminal is full-screen. I'd rather the tab bar disappear completely in full-screen, as it does in Epiphany.
Edit: As michallepicki has pointed out, Terminal has a dconf setting to hide the tab bar for a single tab. However, when there is more than one tab, Terminal always shows the tab bar (even when full screen).
When Epiphany is full screen, the tab bar disappears regardless of how many tabs are on it, giving all available screen real estate to content. This is what I expect when using an application in full-screen.
Ideally, all elementary apps should share the same interface metaphors. I prefer Epiphany's in this case, although it has a caveat: in order to regain access to the tab bar, one must leave full-screen (by pressing F11). If a compromise, allowing the tab bar to hide and be accessed without leaving full screen--such as a pull down, were available, it would be best for both Terminal and Epiphany.
Note: Epiphany's behavior has somewhat changed since making this post. Now epiphany has a pull down in full screen, but it only includes the top bar (CSD); not the tab bar, yet.
I had an idea for a compromise: a pull down tab bar for full-screen applications.
When an application is in full-screen, have the tab bar hide, then slide down when the mouse comes within the area it would occupy.
Firefox does this. When Firefox is full-screen, the top bar and tab bars scrolls up, off the screen. It reappears when the mouse touches the top edge of the screen. Firefox's unhide behavior is to push the window content down to make room.
gsettings set org.pantheon.terminal.settings tab-bar-behavior "Hide When Single Tab"
Epiphany has the same "hide when single tab" option, but worded like this: org.gnome.epiphany.ui.tab-bar-visibility-policy "more-than-one"
This helps in the case of a single tab, but "hide when single tab" in Terminal doesn't solve the problem for me, because I want Terminal and Epiphany to have matching interfaces, which appears to be the intention of the elementary OS design. That means choosing either Epiphany's behavior (hide the tab bar in full-screen regardless of the number of tabs) or Terminal's (always show the tab bar when there are multiple tabs); I prefer Epiphany's because it gives more screen real-estate to content.