I'm a casual fan of science fiction - I know what I like and otherwise steer fairly clear of the genre to avoid the inevitable allegations of puerility and geekdom that my wife throws at me for reading novels about spaceships and little green men.
Brian Aldiss is a prolific British Sci Fi writer who, as you might expect, cares very much about his genre, and in particular believes it to have been unfairly maligned bypeople such as my wife.
While that's probably true, it adversely colours this book in two ways: Firstly, Aldiss writes far too intellectually and "worthily", meaning he comes across as pretentious and (what is worse) dull; secondly, he tends to relegate of material which he thinks isn't "serious" science fiction (but which is generally more entertaining and popular) to other cateogories such as "fantasy" which, to his mind, don't seem to count. I think this is a mistake: Science Fiction at its heart is a poular, pulp sort of genre, no amount of post facto rationalisation will alter the fact that it is Lucas and Spielberg who are the backbone of (cinematic) Science Fiction, not Kubrick and Tarkovsky.
It's a very heavy (physically as well as textually), long winded book. Having completed the first three or four chapters (in which Edgar Allen Poe gets a somewhat surprisingly extended mention) I have given up on the project of reading Trillion Year Spree from cover to cover, and now intendto use to dip into from time to time instead. Or, at any rate, just to stick on the bookshelf, comforted in the knowledge that it's there and I *can* dip into it from time to time, if I feel like it.