I did a quick trial run, and I love it. I'd pay for it. I tried drawing quick sketches on an iPad and pasting it, I tried latex math formulae inside tables; they worked flawlessly. The UI is gorgeous. Lists don't seem to work inside tables though, and most of the keyboard shortcuts don't work for me.

In any case, for the theme at hand, I'd still go for a word processor and a single file combo. It turns out I need more primitives to organise my writing than even typora's markdown gives me, such as colors, formatted paras or lists within tables, tab stops etc. And most importantly, Word has evolved to support really large files, since I have had basically a single diary for many many years.

That said, I will try out typora in earnest for documentation and other things.