Replacing the case's stock fans with the fractal design ones.
Stock rear exhaust fan. Most reports suggest this is very noisy. I personally didn't even bother testing it, so just removed it quick as!
The grille covering the fan on the internal side does not have a huige open area. additionally, the edge finish is very sharp, not high quality at all. Once all the WC kit is in and I have a chance to do some sound intensity probing, I may replace this with a finer grille with rounded edges.
Stock exhaust fan on the top. Blue LEDs on these.. eeeuuugh! dont want no blingy chav PC thanks

supposedly not that quiet either. What I don't get is why it needs the massive shroud above this. Although I like the idea so it protects the PC from spillages above, it just impedes the airflow I would imagine and looks crap. It adds about another 7cm to the height of an already massive case...
Fractal design fan in it's place.
Stock fans in front door. Again, these are chavvy blue LED parts and reportedly not that quiet.
Fractal design ones in their place. It is worth nothing that you will need a fan cable extension for the top fan. The 3 fans connect into a junction box hidden at the bottom of the door, which then connects via one cable into the case. This is then connected to the Lian Li's fan controller.
EDIT: as a note, I have only had the box up and running for about 15 hours maybe (had a company of heroes and cs:source binge until I get to install all the new games!) and the amount of dust already collected on the dust filters is incredible. Additionally, becase the front door is meshed, a lot of the bigger dust gets stuck on the front door, which looks a bit messy. Still, rather it gets stuck on the front door and dust grille than in my shiny new kit
This could be because my room is especially dusty, or it could be because those fractal design fans push a lot of air. I suspect both! however, I have the fractal design fans up full on the Lian Li controller and can report they are inaudible owing to the noise from the graphics cards and CPU cooler. I'll review these once the system is fully WC'd.