I haven't read "The Fearful Summons", but i've heard that it was a major disappointment (the main reason why I haven't read it). Too bad, considering that I really enjoyed TUC...
Something about it being way too Kirk-centric, as I recall. Still haven;t read it.
Not about Kirk-centrism.
It's the novel equivalent of the 1960s Gold Key comics. It was good at inducing WTF!? moments, not good at telling a believable story with recognizable characters.