What shell should I use?

I'd probably go back to perl, and in fact I've back-ported some scripts from ruby (part shell, part ruby).

Issue with shell scripts: commands have different options on BSD vs Linux. e.g. date. If I use coreutils packages, I don't know if other users (or my later installs) will have the "g" prefix.

Issue with ruby (I am a rubyist): 1.9 has broken most of my scripts due to the unicode string thing. Some scripts run as both a cronjob which runs a stock 1.8 ruby, and interactive (1.9) so that results in errors with string parsing.

Perl 5.x has remained the same over the years. Just comment your code enough. There's a perl power tools (ppt) project somewhere on sourceforge that might interest you. Python should be fine, too. I'll investigate these 2 shells you've mentioned.

Edit: homebrew supports scsh. you can try installing the brew. Had a look at both. Both are lispy. What is the benefit of something like scsh for scripting over zsh/bash ?