Ok, I downloaded and gave version 1.6.0 a try.
First, I have OmniCC, but cooldown counters won't show on Mangos. OmniCC is the latest version from WoWInterface.
Second, when I type /mangos or /mg, nothing happens. Perhaps have /mg do what /mg help does now? (I'm guessing the GUI configuration isn't in place yet, which is why /mg does nothing?)
I guess that's about it for now. It looks good otherwise. I've just set it up on my mage, so no bar switching or anything fancy going on, took me less than a minute to be up and running :)
Edit: A quick relog sorted the OmniCC problems!