This story seemed to roll along fairly quickly, but that may be because I knew the Cybermen were in it and was expecting them to appear at any minute. They don't really show until relatively late. I guess with the TV series being called 'The Wheel In Space', there was an element of surprise which is lost in a novel which sports one of the dastardly villains on the cover.
And having read the crucial pages a few times now, I'm still not entirely sure what the Cybermen were getting up to. That is probably my fault rather than the author's (to impeach Terrance Dicks would almost be like having a go at Who himself!). I do wonder though whether other readers felt the same.
Regardless, this story is one of the more important Who tales, following immediately on from Victoria's departure. It details Jamie's dismay at Victoria deciding to leave, and it features the introduction of Zoe, who I think was one of the best ever Who companions.