The current version of the supermemo algorithm is SM-18. The author thinks SRS has gotten way better since the author was previously using an out of date version of the algorithm, SM-2.
SM-17 is linked from the benchmark repo: https://github.com/open-spaced-repetition/fsrs-vs-sm17, though I get the impression those numbers come with a dash of subjectivity. It seems fair to compare to older versions of the algorithm though because SM-17 is only used in the SuperMemo software (and Anki) and isn't widespread.