I recall that in the James Bond Bedside Companion Raymond Benson was quite critical of Icebreaker and called it a significant step down from the first two novels, and perhaps if I was to reread the novel some of the cracks would start to appear. But I can honestly say that I liked it more than a number of the weaker Ian Fleming titles.
That's interesting! I don't remember that bit of what the Bedside Companion said about Icebreaker being not as good as the 1st 2 books, but it was the synopsis from the Bedside Companion that helped me chose Icebreaker as the first Gardner Bond novel to read! Ironically, Licence Renewed, the 1st Gardner Bond, is the only continuation novel that I haven't finished reading because it got tedious for me to read.