Compression.gzip's poor performance

I figured I’d post this here instead of creating an issue on the Akka project, as it’s not a bug, per se, but it has me pretty confused.

I was migrating some old code (to dump databases into text files) to use akka-streams. When the performance took a major hit, I investigated, and eventually figured out that Compression.gzip has characteristics that are way worse than GZIPOutputStream's. At level 9 (default), the speed is less than half of GZOS's, and the resulting files (on my real-world data) were ~33% larger.

I’ve created a readme/sample/repro project here (using fake data with lots of duplication, so the size differences aren’t nearly as pronounced):

Does this merit opening an issue at GitHub?

Yes, please open up an issue to track it, thanks!