How does this compare to BuckleScript or Reason?
The equivalent is fable [1].
The major difference I would say, is that you are required to use botnet alongside of node. (dotnet to compile to JS, then node to bundle with wepback or anything else)
Also, you can use the same language to build high performance backend with giraffe [2] (better than node). And build performant native application with fabulous [3].
There is an experimental typescript compilation. Which will be great, because it will make using F# less hostile in an environment where the winner takes all.
[1] https://fable.io