Maybe I'm missing something, but 500 qps for serving static files seems supremely unimpressive. Fair play about it being more fun, or saving some money from AWS, but I am not convinced that this setup is a good achievement in terms of performance.
Note that my load test wasn't to see how much I could squeeze out of this, but to determine that it's "more than good enough" for this use case. The typical qps I get from real customers on the site is about 0.5 qps, so I think I'm good. :-)