I would say to change your fluid and bleed the whole system, especial attention to the rear calipers which are a bugger. If the fluid has been boiled it wil lnever be the same again. Not sure about the APs but my Alcons have two bleed points for the fronts, so when bleeding the fronts bleed both points starting inboard.
Lastly, I understand that the rear calipers themselves are a culprit in a less than rock solid feel which is why there is a rear AP calipers to replace them. Not sure if you have that caliper of just the fronts?
Nigel Mills - 2.0 zetec