I'll add my approval here. Aeron is fantastic, exactly what you need when building a fast messaging infra. Reliable multicast is a really massive deal.
In a previous role I tried reliable multicast via ZeroMQ's support for PGM and it was a fucking disaster.
Aeron does indeed actually work.
Yeah I tried this as well a few years earlier, didn't get anywhere. Aeron I got to work immediately.
zmq is a challenge to get to work for sure. It's super low level.