My experience was much like Danny's when I updated to a 2 circuit M/C last summer.
Another tip coutesy of my M/C mechanic son: tap on the master cylinder with a ratchet if small hammer in between "bleeds." Knocks loose bubbles that can be clinging to the walls of the cylinder I guess.
BTW, did you pre-fill and bleed your master cylinder? I didn't last year and it was a PITA. I wised up last week when I put in a new clutch master and the bleeding process took under ten minutes.