The Pilot episode is fascinating in its own right, if you look into the events surrounding its transmission, and subsequent alteration for the following week.
As a stand alone episode, it's loaded with mystery and intrigue, you really do question everything, who on Earth are these people, and where are they from, how do they know what they do? It's so imaginative.
Susan's artwork, the whoosh in the opening credits, the clothes, and some of the dialogue, just some of the differences keen eyed viewers will spot.
We hear the name John Smith, I wonder if in The Wheel in Space they looked back at this episode for a reference.
I think there is some real quality to this episode, Susan is a truly interesting character, she's more than just a screaming child here, her very existence is curious here, I liked this side of her character, an advanced girl out of her time.
It's fantastic, 10/10.