One of the engineers who helped run benchmarks and compile the report here. It’s worth noting that for the majority of the machines we benchmarked on AWS, their tested bandwidth met the published AWS expectations. You may have noticed that some of the “network optimized” machines fell short of the published expectations though, and there’s an explanation in the report about how we tried to validate our findings.

As you point out, there are a variety of variables that could be tuned to eek out better performance here, and they could bring the two clouds closer. Our claim, of course, only applies to the benchmark configuration we tested with. That being said, with the size of machine we were restricting our testing to (16 vCPUS), no AWS machine claimed to offer more than 25G of throughput.