I too thought that Mary disturbed the crew in the beginning, but by now she has become essential. Not only does she have good advice but she also has a different perspective. She writes different stories than the others and has experience in the audio-visual genre, with really adds to the podcast (much like Howards perspective based on comics). And, also, she has turned out to be easily as funny and snappy as the others. Also, I like how she often takes up moderating when Brandon is not around; I think she does it better than Howard and Dan (iirc).
In short: I like her on the podcast, keep her!
Five minutes more seem like a good idea, though.