[taeric]

I'd say the big downside is that they don't support the general looking accessor that I'd wager way way way too many people will accidentally use. Myself definitely being one of them. Would have been better if they didn't "seem" to work with the wrong syntax, at least. But, alas, here we are.

[kevincox]

I'm typically using TypeScript so that is more or less a non-issue. But even then it seems like an easy thing to get used to.

[taeric]

Fair. And I didn't say it is a blocker. Just an easy footgun/downside. Is listed on the page linked, even.