Took me 2 full sessions at EC (doing like 2m25's too) and my pedal was getting lower and lower and then on the cool down lap it totally disappeared to the floor, had to use the handbrake to pull up in the pits (about 15min later after doing afew laps of the carpark).
Work done:
* All 4 calipers overhauled (seal kits).
* Front Goodrich braided lines
* New master cylinder (after 6mths of mucking around with getting the original bored and sleeved, never do that!!)
* New fluid
* New pads
Yes, fun
You definitely want overkill on your brakes. If you lose power you just slow down and pull over, if you lose brakes you hit a wall