It's nice to edit the same file from two different views. I use a vsplit for this, as described here, and it works well.
However, I'd like to have the two views open in different terminal windows, because I use a tiling window manager, and I've already got the muscle memory to switch between two open
vims using the window manager's hotkeys. Also, it's easier to tell which one is focused, because I've set un-focused windows to become transparent.
I can open the same file twice, but then changes don't propagate from one process to the other until I save.