it tab completes more than bash does. switches, parameters, servers defined in your .ssh/config file etc. it's really impressive. coupled with the jump/mark script[1] it's amazing.
mark . marks the current directory in a folder full of symlinks.
jump <tab> expands to a list of your favorite folders.
Well, bash tab-completes with arbitrary complexity, seeing as it can be set to call functions... I assume the same is true of zsh, so the real question has to be adjusted for particular setup. There are a number of interesting questions of that form. Off the top of my head: The minimal setup I get from simplest packages in distro X at time Y. The maximal setup I can extract from distro X at time Y. The typical install I am likely to sit down at if it is not my own. The setup I am likely to evolve to after working with the system for it for time T...
mark . marks the current directory in a folder full of symlinks.
jump <tab> expands to a list of your favorite folders.
super simple and extremely low overhead.
[1] http://jeroenjanssens.com/2013/08/16/quickly-navigate-your-f...