I put about a third of a bottle through the system. Four pumps on the pedal, top up, another four, rinse and repeat. It's odd, because the fluid in the reservoir didn't look nearly that bad, and there was only a really fine 'waterline' of mess to wipe out when the level got down.
Some of the photos I've seen show black gunk in the reservoir and all through the system, so I'm glad it wasn't that bad!
I have a nice new clutch and flywheel that I bought at a 15% discount. I'll get it fitted sometime in the summer, then the only thing left to do is discs and pads if I decide to be really fussy. I could have just polished it and flipped it for what I paid, but I kinda like the FN2, I might stick with it until 370z's get down to around £7k!