I agree that the default level (6) for xz probably errs too much on favoring file size over speed. My tests with compression levels 1-2 do indeed show modestly

I agree that the default level (6) for xz probably errs too much on favoring file size over speed. My tests with compression levels 1-2 do indeed show modestly improved size and speed performance relative to single-threaded bzip2. The fact remains, however, that I can't seem to find a simple way to install a parallelized version of xz. Perhaps I'll post an issue in the Github issue tracker for pixz and see if we can't resolve that. :)