[pjmlp]

Orleans was born to support Halo's server backend and went from there, they know their stuff regarding performance.

> Orleans is used by Microsoft in Azure, Xbox, Skype, Halo, PlayFab, Gears of War, and many other internal services. Orleans has many features that make it easy to use for a variety of applications.

https://learn.microsoft.com/en-us/dotnet/orleans/overview

Until Ractor proves itself in similar workloads, it is a tiny bit more than syntax sugar difference.