[tripflag]

I always use "zstd --long=31 -T0 -19" to compress disk images, since that is a usecase where it generally offers vastly superior compression to xz, deduplicating across bigger distances.

XZ offers slightly better compression on average, but decompression is far slower than Zstd.

[dralley]

IIRC memory consumption is generally worse for Zstd at comparable levels of compression. Which, these days, is generally fine, but my point is you can't thoughtlessly substitute the two.