GreiginFife
Money List Winner
This is what mine have. For the most part they rely on mapped limits controlled by GPS but they also have an over-ride from the camera (for things like temporary speed limits or ones that have recently been changed). Although I don't have this linked to the limiter on either, I do see the limit signs changing in the HUD and can amend my speed accordingly.I imagine the newer ones are - mines 8 years old and uses some sort of camera or sensor where the rear view mirror is.
A combination of the two would probably be best as the GPS limiter may not pick up temporary speed limits around roadworks etc.