The apps he demonstrated loaded much faster on the 6S, as expected.
As a web developer, I shake my head whenever I see web pages used for benchmarking device performance; two identical requests could take vastly different amount of times to complete due to a multitude of variables: ISP connection, network congestion, DNS lookups, which servers handle the given request and their instantaneous load, which assets and ads are loaded, etc, etc.
If you want to test the browser, there are real benchmarks that preload everything to the device for consistent results.
But then the results wouldn't be controversial.....