Depends ;)
The disruptor allows you to decouple various different actions, and potentially perform them in parallel. So the question is how expensive is your business logic and how bursty is your workload? The Disruptor is used to transfer data between threads, specifically threads which are potentially running at different message rates. I.e. it allows the producing thread to produce a burst of messages while the consuming thread is busy handling the last message.
For instance if you also wanted to persist your message to database as well as sending the result onwards you could publish the message to a "outbound" ringbuffer and have your netty code consume from that as well as a DB persister.
The less time you spend doing things in Netty's eventloop
the more clients you can cope with, or larger messages volumes at the transport level.