I use a MacBook and can confirm 100% that MacBook & MackBook Pro do use 6bit LCD screens giving you not millions of colours but only 262K(256K) of colours.
They use tricks that can at best give you the impression of 16.2M, not far from 16.7 of a 8bit LCD screen, the screen itself dose the trick
Manufactures of these screens say they are 262K and computer manufacturers like Apple, Dell, HP etc quote millions.
So you see dots in dark black areas it is normal it is only 6bit, not realy that bad and you will only notice it on dark areas or like the OS X shadows on it's windows as it moves over areas of the screen.
For MacBook SRMB Model you will get a profile that is not as good as the previous MacBook and best off using the Profile for the LG pannel the newer MacBook uses a AUO pannel that has a better responce time and is brighter but they ship it with a poor profile
Profile for LG LP133WX1
Profile for AUO B133EW01