Woohoo! It worked!
No seriously, I am so happy of what I have done right now.
I can barely complain about anything, if it's just about the fact that the case is finger prints magnet, that I was missing a couple of screws and that I think I heard a bit of coil whine during 3D Mark but it stopped.
If you ask yourself if you should do it: DO IT! You will be amazed.
EDIT: There almost ain't any sag, bad camera angle made it that way! :-)
Replaced radiator fan with SP120 fan.
Got a new monitor (and I'm in love with it). I'm now dual monitoring with the old Dell screen which is fairly enough. All a can say is: wow!
Got a new mouse pad which is very cool. It's the Razer Goliathus.
I completely rerouted the LED cable to offer maximum illumination.
Pictures of the updates are coming soon...