Unfortunately though, Horse Heaven is about 200 pages too long. It's wonderful and lots of fun to read, but at some point you realize that you just kind of want it to go home now. And then you start to feel somewhat exhausted by the gigantic, sprawling cast, and to feel a bit confused and muddled trying to remember who did what when, and then when the end finally comes, it's a bit of a relief. Because ultimately, it's a huge, sprawling novel (it clocks in at 561 pages) with no one particular plot arc. And on the one hand, I really admire this aspect of the book, that it's basically like just hanging out with a bunch of people for awhile and seeing what happens to them, even if it doesn't lead anywhere in particular, but on the other hand, it also makes the cut-off point somewhat arbitrary. So even if you do like the characters a lot - and you truly do, or at least, I did - there's not really a compelling reason to keep reading once you get kind of tired. All the same though, like I said, I do respect the way that Smiley resists the urge to give everything in the text an epic feel, and rather emphasizes the quotidian nature of even the most major events of the text. It's an impressively disciplined realism, no less compelling for being under-played.
What is truly remarkable about the book are the moments when it's narrated from an animal's perspective. It's utterly believable, and an absolutely brilliant use of indirect discourse. Rarely does one encounter a text that so perfectly insinuates itself into a creature's mind in such a marvelous and convincing way. In fact, my favorite characters ended up being horses.
Also, the book wonderfully renders its milieu, the sub-culture of horse-racing, and in such a subtle way that even days after reading it, you realize that you've actually started looking at the world in a new way, inflected by its perspective. It's the mark, I think, of truly great prose when that happens.
Ultimately, it's an enjoyable book, but not as rewarding a read as the other, shorter works. It's not that I don't recommend it, but perhaps you need to be an advanced-level Smiley fan to find it worthwhile.