Yeah, I've read somewhere the new internal oscillators are supposed to be better than the old PICs.

Some things to also keep in mind for really time critical applications - temperature of the oscillator which is manageable, but also acceleration if the oscillator is used in a dynamic environment. This includes substantial vibration. It has been suggested by some that this is the primary reason why all off-the-shelf GPS/GNSS modules are nominally limited to 4g acceleration before losing positional lock.

Troy