In one of the other threads, someone pointed out some of the TOS scripts original outlines in the Orion Archives.
Lets see if I can work out how to post a link http://www.orionpressfanzines.com/articles/spock.htm
The original premise for Spock's Brain didn't seem as bad as the finished product. I just think they tried too hard to engage the audience by including Spock in every single scene. Sometimes less is more.
If we didn't have Zombie Spock or Spock assisting in his operation "Spock's Brain" wouldn't have been nearly so bad. OK I agree and half as long.