Tom Baker was the Doctor for 7 years, and to many around the world, he is the best there's ever been. This story was surprisingly good for it's era, but made so much better by Tom's performance – you'd think he had been playing the part for years already.
I must say that I was a bit disturbed by the costume-choosing scene – I sure hope it was meant to be a joke…because if not…(shudders)
Is it a good story? Yes. Are there plotholes? Yes. Did they wreck the syory? No. If you're a fan of the show, or of Tom Baker in the role, you'll be happy with this serial.