I'd suggest making minimal changes using the built in calibrator.
I tried to using the built in calibrator but it almost seemed kind of pointless on the actual laptop display, since it is portable you (I don't) ever look at the screen the same way, sure it is a similar angle but it isn't the angle that I calibrated. I did however make minimal adjustments using the calibrator and I calibrated my external display but I don't think it'd be possible to make the MB's screen as sharp and crisp unless you were leaving it open and in the same place.