The most recent addition to the Poul Anderson blog, "Cadet Loftus And Ensign Flandry," (see here) summarizes a passage in Blish's The Star Dwellers (London, 1979) where that novel's central character, Jack Loftus, is said to have read a kind of fiction that sounds as if it could well include the Flandry series. I could just copy that post here, as with some others in the past, but I am now trying to refer readers of each blog to the other.
The Flandry series is more or less implausible space opera of a kind that is well critiqued in the relevant passage of The Star Dwellers but what is important about it is that it is very good space opera and hard sf and social commentary, thus not a body of work to be summarily dismissed as "'...nonsense...' " (p. 49).
Since The Star Dwellers was written as a reply to Robert Heinlein's Starship Troopers, anyone interested in serious science fiction would do well to read in succession:
Heinlein's five volume Future History;
Heinlein's fourteen juvenile novels, including Starship Troopers;
Anderson's History of Technic Civilization, including the Flandry series, now republished in seven omnibus volumes;
Blish's four volume future history;
Blish's two Jack Loftus novels.
There is more, of course, but I have just referred to thirty two volumes as a starter.