Well it took just under 500ml (470ml maybe) and it appears to be flushed - colour changed from honey-amber to light blue (new fluid). I did pump the brakes a few extra times to make sure I got more blue coloured fluid out.
One thing I found strange is that there are only 3 nipples - RL, FL, FR with none on RR. I thought there would be 4. It appears the brake lines to RL go via RR. I don't have ABS.
There were no air bubbles and no spongeness when test driven
It seemed nearly too easy...