I just had one for my Birthday, Kalimon. Same situation - hard to buy for!
Going to fit it this afternoon and will be back with a GTD report.
What's the update Dan?
I didn't fit it yet sorry Stevie. It was pouring with rain and I've then either been working or catching Pokemon. 
Will attempt to fit either today or tomorrow!
Or...
yesterday 
Fitted last night, only took 10 minutes in the dark with my phone as a light! Rebecca's photos from this thread were a massive help:
http://www.golfgtiforum.co.uk/index.php?topic=276517.0I was fortunate and the connectors came apart and went together easy, so no issues there.
I've just been out for my first drive and played with a few settings. It's definitely a big improvement on the standard GTD pedal response - any perception of lag seems gone, and laying down power is like small gentle squirts of the pedal - instead of flooring the whole thing.
It gives the sensation of a heavier pedal strangely, I guess because it is responding to you so much more directly. One strange side effect is my brake pedal now feels very soft by comparison!
Having the box in the drivers glove box makes adjusting it very easy too, almost like it was meant to be there!
After trying all the modes I have settled on Sport 0 (no extra lights) for now. If I go any higher the whole car thumps with a surge of torque at the smallest press! This was when testing in the Golf's sport mode and 3rd gear at 2200rpm, and no doubt the extra torque of the DTUK box is to count for this (which is running in 2 +2 mode).
Once I get used to it I may find I can use a higher setting, but I'm not sure my passengers will appreciate getting thumped in the back quite so often if not

Interested to hear your experiences Stevie with your similar car setup to me.