Setting final output

[eluser]Madmartigan1[/eluser]
In reality, we're loading a normal template, just with the maintenance message replacing the actual content.
Some parts of the site still need to work as normal, it's not a "true" maintenance mode. We do this for sites before they go live so we can still work on them on a live server without hassle. (Admins don't get the warning message). It's also used to pull the plug on a deadbeat client

I've never used _remap() in MY_Controller, I think I will try it.

The main thing I'm wondering about is that set_output() is not the solution that I thought it was. Either I'm using it wrong, or the docs are deceiving.