I've had good success with akka at multiple companies. At Protenus the core ETL is based on akka streams. Which has worked great. No notable issues. Tho we don't run in clustered mode.

At glngn we didn't use akka streams (outside of akka http) but did use event sourced, persistent entities powered by akka typed in clustered mode. Deployed to k8s. Which definitely took effort to set up nicely and enable smooth deployments. Our clusters were not huge so many problems did not show up (split brain).

I haven't used other systems that provided an equivalent to akka typed persistent entities. I can't compare akka in that sense. However the event sourced persistent entities model is really, really effective. Definitely a different paradigm: some stuff is trivial that would otherwise be a trial.

I suspect many of the benefits could be achieved by using something like Kafka feeding non clustered nodes. But never tried.