I can remember watching Dr. Who with Tom Baker in the 80's on PBS also and I was struck by how long winded and slow the stories were and how low budget the effects looked. Mostly tuned in as there was next to nothing to watch on Saturday night cable tv but that all changed when the companion Leela played by Louise Jameson came on. Wow. That changed the whole dynamic of the show for me and gave it some spark with the interesting interplay between her and the Doctor(though I hear Tom Baker didn't like her character). I would call this a pre Seven of Nine moment when one character comes on and brings a series to life.