My experience is that width is faster than height to type- mostly from lack of time spent indenting. This is _completely_ fixed by using a decent auto-formatter, but at least for me the bias towards width lingers on, because it took me years to notice that I needed an auto-formatter

May be faster to type - but does it matter? I have never ever been even close to being bottlenecked from typing speed. The only difference is that I "buffer" between lines or between different segments within a single line (but possibly both).