I was using the pressure bleeder kit from eurocarparts - its almost exactly the same as the Gunson Eezibleed - which is not a vacuum bleeder BTW - its a pressure bleeder which pressurises the fluid into the master cylinder reservior. The very first bleed I did was with the callipers not attached to the carriers, but holding them in hand whilst rotating the callipers in various orientations to get all the air to come out of the bleed valve. I then fitted the callipers properly to the carriers, with pads fitted etc. Bleeding again, fluid was flowing through nicely. Initially with air bubbles coming through the pipe (this was new callipers after all, so I expected to see a lot of air at first) - which seemed like it was coming through for ages, and I never thought it would stop, but then I then slowly pumped the pedal whilst it was bleeding, and the air soon went away, and I could see only clear fluid coming through. Same on the other rear brake and the same a second time (with no air coming through at all on this second round). I then bled the two front callipers. No air came out at all.
At no point during the calliper replacement has the fluid in the master cylinder run dry, so i do not imagine I would need to go through an ABS bleed (using VCDS), but I am open to suggestions on this front. As it stands, the car has been out of action for nearly 2 weeks (waiting for parts and tools etc) now and I'm getting a bit frustrated with it. It has cost me over £600 in parts and tools and the last thing I want to do is limp it to a garage for them to bleed it now.