Your drawings should be identical as long as your units and any templates/start parts being used are the same. If they aren't, then maybe you inadvertently moved the component in the master model setup.
The main reason, in my opinion, is so you can change components (models) without losing as much associativity and you're able to reposition the component in the drawing model without moving it in the master model. Say you have a part modeled out on the middle of nowhere and it's not oriented to a standard view orientation (TOP, FRONT, RIGHT, LEFT, etc.). You can add the model as a component to a new file, then use Move Component to reposition it accordingly so your model views align with drafting views. You can also add additional components to the drawing as well but manage them separately in different model files. Reference Sets can also be used with the master model concept.
I'm sure there are other advantages, but for now they escape me. Feel free to seach the forum on the terms 'master model' because this has been covered many times over the years.
Tim Flater
NX Designer
NX 8.0.3.4
Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB