I’ve had no problems with Typescript in that regard (in fact the typechecking and linting is astonishingly fast) but I’m using Sublime integration. From what I understand though, VSCode has very thorough Typescript support, given its Microsoft pedigree and all.

> I tried Flow with VSCode and found it rather flaky. Had to open up files to get autocomplete etc.

Sounds like an editor issue. Have you tried it with something like IDEA/WebStorm where there's a bit more code intelligence?