Tried this out on Friday, bought a Limited Edition C5 and got £100 off using this code (price was £460, reduced to £383 after VAT was taken out and then reduced to £283 + £12 shipping (about AUD$500). Not sure why the code worked for me (should only be for over £500 purchases) but it seems to still be working.
From what I have heard/read they are great quality watches for the price. Often suggested on many watch forums for those looking to spend $500-$1000AUD on a good quality (and automatic) watch.
First post, hopefully I did it right and someone else can take advantage of this great deal!
Unfortunately I have no idea when this deal started or when it will end.
FYI: be sure to do this through the ".co.uk" site and not the Australian site as the Aus site has a rather large price increase and I can't confirm if the code will work in the Aus store.
The automatics are great value watches. The Moonphase models particularly look fantastic. Very solid deal. That DB4 model is jawdropping too.