[headwayoldest]

The biggest thing that swayed me to stick with (and optimize/customize) Prezto was the fact that most of the systems I work with have zsh, or a relatively modern version of it available in repos. Can't say the same for fish.

[ufo]

If you don't mind adding external repositories, you can get up to date versions of fish for most distros.

http://fishshell.com/#get_fish_linux

[headwayoldest]

More a question of corporate best practices than minding, but I appreciate the link!