I read this earlier today. It's a strange book. I think it had the potential to be a GREAT Bond tale, but never fulfilled it's promise. "Robert Markham"'s style is not as assured or unique as Fleming's and one gets the feeling that he was purposely trying to emulate that.
The story itself seems to be a mishmash of Casino Royale and Dr. No in that it's pretty streamlined and straightforward (aswell as having a torture scene, a good portion of the story set on a boat among other similiarites).
Fleming wrote some nasty sequences with a devilish glee that stopped them from being offputting. "Markham" doesn't really have that same gift.
I'm glad I read the book and with a bit of tweaking I actually think it could probably be worked into a pretty good Bond film.
At times I enjoyed it but other times I was frustrated by it. I have to admit I was somewhat glad when it was over.
I don't know what else to say on the subject really.