No sane person would use a fullscreen laptop, unless perhaps their ONLY task was programming. Even then, it makes more sense to me to have my vim window take up half the screen and something else relevant, say a browser, take up the other half. Fullscreen is dead, please don't try to bring it back.
Vertical halves or horizontal halves? Personally, I use maximized vim and browser windows. Alt + tabbing between vim and the browser is trivial, but I need the extra screen space for vim because I often need to split vim between several files. I'm sure I don't need to make a case for how alt + tabbing between different vim windows quickly gets old.
In that case, if you have a widescreen you can have two :vsplit going; on fullscreen there probably won't be enough columns for that. FWIW, my personal preference is having vim full-screen on one of my widescreen monitors which is rotated into portrait view. I routinely have four or more :sp windows going. Once again, far better utilization than with fullscreen.
