Orleans is awesome and the virtual aspect of the actor system is something that I have found to be missing from many alleged comparative libraries (Akka, Actix, etc.) It is really the key selling point: run an Orleans cluster and then you can forget about networking altogether (not entirely true, but truer than you may believe.)

Just don't make any bugs in your code or you're in for a headache.

The ergonomics of Orleans are so nice in fact, it inspired me to try to achieve a similar effect (any POCO can be invoked across the network) by using IL weaving. It worked, but it's SCARY.