The developers I've encountered that use F#'s Async get confused at first mainly because they are used to C#'s Tasks being started upon creation. I personally t

The developers I've encountered that use F#'s Async get confused at first mainly because they are used to C#'s Tasks being started upon creation. I personally think the F#'s model conceptually is better and I've seen more surprises with the C# one from dev's I've worked with (e.g. which SynchronizationContext is set and why does it work in my test but not in the app, why is there no trampolining and I'm deadlocking here, why do I need to pass around CancellationTokens everywhere, etc). There are benefits to the F# async model (execution) such as implicit cancellation token parsing from the root task which is much harder to implement if the Tasks are already started before you finish the root, that they are re-runnable, they can run on whatever context you want easier at the composed root level, and the fact that it uses a more generic feature in the language (which usually comes with a slight performance overhead). Both F#'s Async's and Tasks aren't the best for CPU parallelism IMO anyway - my impression is that they are for using up idle IO time across a number of threads more efficiently. An article which I think compares the two despite it being biased a little to F# rightly or wrongly: http://tomasp.net/blog/async-csharp-differences.aspx/ http://tomasp.net/blog/async-csharp-differences.aspx/