A few (cosmetic) details, for example:

- They don’t support multiline item descriptions. They actually prohibit that for a specific reason, because you can’t sort the lines lexicographically anymore. In my opinion, that should be an optional feature, however, which it is in [x]it!

- Creation and completion date are featured prominently, but I actually think they are not that important, and I’m not sure they are really worth some dedicated syntax. What I do find important, though, are due dates, and these are not natively supported in todo.txt

- I don’t like the notation of just preceding `x ` to the line for a checked item. It’s simple on the one hand, but it doesn’t look very tidy in the file.