This is especially true when using a tiling window manager such as wmii.
In that case you don't even have to rearrange windows - each new window automatically takes part in the split. And you can combine terminal sessions, browser, etc. as you wish. I find this a lot easier to use than screen/tmux.
I'd love it if there would be graphical frontend to tmux or screen. Something that would look very much like a terminal emulator, with tabs and splits, but backed by screen or tmux, whereby each tab or split window would be a tmux or screen window. And the awesome part is that when you're elsewhere, you could ssh in and attach to that tmux or screen session.
How far you take it depends on what you'd want out of such a tool. Simple "New Shell", "Close Shell" buttons would be easy; overlaying draggable partitions would be more effort, and less elegant, but still do-able.
After using emacs a lot I've ended up preferring screen splitting.
I used to be happy just running multiple xterms, but I've been using Linux again recently and found myself a bit unhappy with that. I think due to advancing age I'm just finding it hard to cope with lots of windows. Keeping on top of them is a pain.
The main difference with the other terminal emulators is that I can easily do horizontal and vertical window splits.
Many use screen or tmux for that but I find them too limiting, especially in their scrollback implementation.