What gives it the extra oomph, for me, is the fact that it's also one of the best renditions of contemporary life in Europe that I know of, in terms of racial and cultural relations. In other words, the novel actually registers the presence of immigrants, but without making it seems as though that's the point, or in a token "this is my immigrant friend" sort of fashion - they're just undeniably there. But the power relations underlying them also make an appearance, as when the main character is made somewhat uncomfortable by a Nicaraguan janitor telling him that he's working too hard. Likewise, it's an honest depiction of race relations - the main character is falling for a black woman, and finds himself somewhat hyperconscious when back in Belfast and is wondering whether its because she's the only black woman around or whether it's because she's so incredibly attractive. Later, they meet another woman who has never seen a black person from up close and is enthralled by the smoothness of her skin. It's a really gentle, honest version of how people of different races and cultures interact in a heterogenous world.
Interestingly, I think this is also one of the first novels I've read that has Unionist characters - I've read books from the North, but pretty much always from the Catholic side. Not that this novel is especially partisan (though some of its characters are) - if anything it registers a kind of weary sadness about the whole thing. Again though, I was impressed by the way that the novel drops these political observations or memories or just a kind of awareness of politics into the flow of its story. It captures, I think, the actual experience of living in the world - where politics isn't necessarily your central concern or THE drama, but it's still sort of present in your mind and pops up here and there.
Overall, though, this is basically just a very pleasant read - but an intelligent one.