OK, so I didn't end up getting those things deleted. I asked for it, but upon physical removal of exhaust ahem thing and sensors and bolting in a straight pipe it threw all sorts of codes, had to reinstall the *ahem* thing.
I sent GDE an email, because I specifically asked for the delete to be included. They have not replied yet, which is unusual.
The tech I was dealing with in brisbane was on holidays, so I'll have to wait for the till after Easter to get him to chase it down for me.
No removal of computer required. Just plug in the flash tool, boot it up and bobs ya uncle. An ape could do it, really, it was very, very easy.
As for improvements?
I feel like it's smoother, tons more powerful, shifts more appropriately, very little lag and a huge difference in fuel consumption... The website for green diesel boasts a 2-4mpg increase, this is definitely not an exaggeration.
There is more engine noise, you can definitely hear the turbo a bit more... But hey, that's a nice thing