here’s an idea that I thought of for quite some time. It is that i often hear when I show a CUBA app to people, the first response is “this looks like a Windows application”. And with that it get a little bad reputation because “web application don’t have this title bar in 2018” - if you know what I mean. It is mainly that the normal layout looks a little bit dated.
I normally use the “Main Window with responsive side menu” in my apps, because first of all it looks a little bit newer.
Also it takes the aspect ratio of normal screens more into consideration. Normally there is less space regarding the height compared to the width. Therefore putting the menu to the side leverages that fact.
Since you already introduced the side menu layout quite some time ago, it might be a good point to switch in 7.0 to give the newly applications a little “fresh look”.
It is not so much regarding the effort that has to be done to get that look for your own app, but rather the overall first look experience will probably be improved for people looking at it.
Interested to hear what other people think.