Asciidoctor has been much better received by my colleagues, primarily for the built-in support of a few technical writing features — admonitions, non-trivial tables, crossreferences, etc.
Multimarkdown has similar features so far as I know, but it has the same problem as Markdown.pl: written by one person, with a bunch of spot fixes and so isn't really reproducible or extendible by anyone else without running into bugs.