I've been primarily writing Kotlin for the last.. uhh, 3-4 years I guess. TS and VSCode pairing is good, but Kotlin + IntelliJ is both more faster and accurate in terms of knowing what you want and when you want it. Autocomplete, code generation, refactoring, moving works so good it is a huge productivity boost. And the "peeking" at types (the implied type is shown in a small gray box) lets you keep your code clean but very readable.
Honestly, considering that JetBrains wrote both Kotlin and IDEA, I'm often surprised at the little papercuts when editing Kotlin code.
I can't tell you how many times it has autocompleted FooClass.Companion.functionName() for me and then immediately suggested that I should remove the Companion part. "Ya think?"
The performance also doesn't seem that awesome for me. It doesn't require a very large file before it starts taking several seconds to highlight and analyze it. Granted, I haven't upgraded to 1.4 yet, which supposedly improves performance.
All that works well TypeScript as well. The difference is that Kotlin only really works well in IntelliJ. TypeScript works well in both WebStorm/IntelliJ and VS Code.
Autocomplete in VS has always been kind of 'meh'... Works OK for Go, should work fine for TS (until your type packages are off, in which case good luck to you), but IntelliJ code completion for stuff like Java and Kotlin is just on another level.
It's very hard to pin point, but if you're developing a large project, you'll notice when autocomplete works 100% of the time (IntelliJ), and 93% of the time (VSCode).
I've been primarily writing Kotlin for the last.. uhh, 3-4 years I guess. TS and VSCode pairing is good, but Kotlin + IntelliJ is both more faster and accurate in terms of knowing what you want and when you want it. Autocomplete, code generation, refactoring, moving works so good it is a huge productivity boost. And the "peeking" at types (the implied type is shown in a small gray box) lets you keep your code clean but very readable.