I tried using oh-my-zsh, but all of a sudden bringing up a new terminal (on OS X) went from taking ~1 second to ~5 seconds. Totally killed my interest in zsh.
I'm sure there's a way to make it all work nicely, but bash has been doing just fine for me, I don't feel the need to figure out an entirely new configuration system for a tool that ultimately has little new utility in my workflow.
I'm thiiiiiis close to going back to rc, because when there's any kind of load on my system it can take multiple seconds for a new xterm to open with bash. rc starts in no time, and I already use it when I have to write a quick one-off script.
Honestly I do not understand the purpose of oh-my-zsh. I've been using zsh without it for years, if I want something for it I just take 5 minutes on google to figure it out. No sense in having a lot of stuff turned on by default that I don't know how to use.
I feel the same way about Vim, but for some reason more people in the Vim community seem to agree with me.
There is a cleaner 'version' (==fork) of oh-my-zsh that fixed the long startup time for me: https://github.com/sorin-ionescu/prezto. With nice, fast setup (overwrites your .zshrc file!) and lots of documentation.
Same thing on a year old MBP. I installed the basic Oh My Zsh package and a new terminal sometimes takes 5-10 seconds to initialize. Are there some tricks that would make it faster? I mainly use the Git-plugin.
I'm sure there's a way to make it all work nicely, but bash has been doing just fine for me, I don't feel the need to figure out an entirely new configuration system for a tool that ultimately has little new utility in my workflow.