How to bleed brake system after master brake replacement

[Ivan141]

mmmkay...Just started bleeding all four calipers, starting on the rear axle, working my way forward. The pedal is a lot harder now, but with the booster assisting the pedal when the engine is running I notice that it still makes the first centimeter of the pedal stroke soft. When driving I get better response from the brakes, but it's weird that when I press it fast, the first bit stays mushy, and when I press it slow they feel a lot firmer.
Maybe there is still some hard to get to bit of air somewhere or I need to install my new discs and pads (current ones are worn down by 50-60%), but I'm not completely satisfied until my brakepedal feels hard on the first bit of the pedal stroke with the engine running.
This is about as good (or better) as I have ever felt the brakes on my car so I'm not dissapointed, but I have felt the brakes in robokills car, and know how they should feel in good order.