I'm a fan of cluster ssh. It allows you to control multiple ssh session with one keyboard. I tried csshx which uses the default osx terminal, but I love iterm2.
But today I found i2cssh which does that for iterm2
One of the feature is broadcast where you can send command to multiple window. It's basically the same with csshx but their approach is to create another extra window that receive an input and send it to all other windows. I like i2cssh approach better with shortcut.