To be honest, I never heard of the author until I read about him in a Best-Ever-SF-List. 'Hello Summer, Goodbye' is considered to be his most succesfull work and after reading the novel, I cannot do otherwise but praise the book. The work is no classic SF and more soft than hard SF, describing a world which is quite similar to our earth, with a stage of development that makes the book - technically speaking - one of the first steampunk novels. The author was also clearly influenced by the cold war, as two nations are warring each other constantly. All this takes place on a world which is fluctuating between long summers and long winters. The plot starts as a summer holiday at the sea, describing a teenage boy who is struggling with his parents and falling in love with a local girl. More and more external factors are influencing the young folks and the inhabitants of the fishing town, and in the end, the summer goes, with bitter implications the reader couldn't think of at the start of the book.
What I liked especially ist the melancholic undertone of the novel. The author takes time to tell the story of summer days at the sea, with the protagonists doing boat trips and discovering the adventures of the coast. The main characters, especially Drove the teenage boy, are described very well and are evolving considerably through the 230 pages of the book. I think if I had read the book in my teenage days, I would habe been impressed even more than now. The only thing which seemed somehow undrealistic for me is that Drove is analyzing his surroundings in a very rational, sophisticated way - but maybe that fact makes him one of the first nerds and gives him the affection of the reader. 'Hello Summer, Goodbye' is a very compact but nevertheless very moving book about the end of youth on a distant but not so far planet, and if you aren't into Hard-SF only, you should definitely give it a try.
** UPDATE ** After re-reading the book, my opinion remains the same: a sad and beautiful coming-of-age novel in an unusual science fiction setting. No summer lasts forever. What struck me even more the second time as somehow incongrous was the adult voice of the first-person author, which doesn't really fit with the adolescent protagonist. I had also forgotten that the book has a rather explicit sex scene, which comes across rather embarrassing, as the choice of words and description sound like an older man and not a young adolescent. So the first-person perspective and the omniscient narrator sometimes get in each other's way. Despite these minor flaws, it's still one of my favorite books.