Agreed. This is much more of a test of the rails framework then ruby

Well, it's a comparison of different ruby versions, using Rails. That's pretty useful to people who use Rails, which is a lot of people.

Of course, it's not a real Rails app presumably, but just a sample/dummy one. So you may or may not see comparable speed-up with a real app. But it's probably suggestive of the upper limit of improvement you can get by switching ruby versions.

"Will I get a performance improvement from my Rails app by upgrading ruby" is a real question a lot of people will have. Micro-benchmarks of ruby wouldn't answer it as well as the OP does.

Not really since it does not compare it to another other benchmarks. This is a test of how the performance of MRI ruby has changed over time.

If you test small features, you get knocked for concentrating on microbenchmarks which don't have any real-world meaning. If you test whole applications or frameworks, you get criticised for benchmarking that rather than the language implementation.

The criticism is with the name, not the features tested.