That's exactly what I do with Gnome Shell. Depending on the day, I have the terminal on one side and the browser on the other, or simply a half-screen terminal

That's exactly what I do with Gnome Shell. Depending on the day, I have the terminal on one side and the browser on the other, or simply a half-screen terminal over top of my browser and I flip between them. When I launch a graphical app that I am working on for testing, it appears behind, and so I just flip the terminal from one side of the screen to the other as needed, or bring it to the front if really necessary. I would say that the _only_ thing I'm missing in Gnome is the ability to fit a window to the quarter screen, although I believe there are some plugins that can do this.