Another thing: you are only using one thread for both the client and the server, and the app writes the entire content in one go (during one call to get()). Wouldn't it be more interesting to make the app's get() method asynchronous as well, so that each chunk actually gets passed separately? Otherwise, the fact that it's writing chunks wouldn't really contribute all that much to the benchmark.

Or maybe split it up into two benchmarks, one that exercises the asynchronous client (as your current code does) and one that shifts more work to the server side? Not sure if it's worth it, but might be worth trying. I think it would cover two different use cases that way.