There is very little YA science fiction that's not dystopian, and there's extremely little that's in any way hard or based on rigorous extrapolation. There's no real good reason for that; it's just that YA fiction exists in its own little world, and it tends to be really trend-driven and, so far, no one's published a hard sci-fi YA that's really blown up and become a hit.
That being said, a number of established SF writers have published YA novels that're pretty good. I've read two of Cory Doctorow's other YA novels: Little Brother and For The Win. And I've been known to recommend Little Brother to people who're looking for that sort of thing. You know what I mean: books that are sort of science-fictiony and sort of techno-thrillery but aren't exactly cyberpunk. Books that are just good, honest fun (in my mind, these books are synonymous with Cory Doctorow and Neal Stephenson).
Anyway, that's enough rambling. The point is that in the last few days I've read two Cory Doctorow novels: Homeland and Pirate Cinema. And both were absurd. Homeland is a follow-up to Little Brother in which the protagonist has to organize yet another grass-roots hacker-based resistance movement to yet another government incursion into civil liberties. What's fun about Homeland is that all the bad government things are more or less true. Our government does snatch people up and torture them. It is corrupt and intertwined with certain corporations in really creepy ways. And almost all of the technology described here is also real.
But there's something so earnest about the book that you almost want to laugh. For instance, the first fifth of the book takes place at Burning Man. And the book is completely unironic about it. The book is like, "Yeah, we are at Burning Man and Burning Man rawks. I wish the entire world could be like Burning Man." The book is like every conversation I've ever had in mid-September with someone newly-returned from the playa.
Secondly, the book takes place in a San Francisco that is not our San Francisco. This San Francisco is a rough and tumble, economically depressed, working-class place where people drive beaten, barely-functioning cars and nineteen year old hackers have trouble finding work. It actually resembles Portland more than it resembles the SF that I know: an SF that is full of 22 year olds who earn $150,000 a year and lead lives that combine the downtime hobbies of a bohemian with the work ethic of a Japanese salaryman. There is basically no vestige of the bizarre money-driven SF tech-world that I know.
But it's still good fun!
Pirate Cinema is, if anything, even weirder, because it takes place in a true fantasy land. In this near-future London, sixteen year old teenage runaways lead amazing lives! They just take over abandoned pubs and hang out all day. Food is scavenged for free. Electricity and water and internet get scrounged up somewhere. And they just lie around and go to parties all day. I'm not exactly the world's greatest expert on street kids, but from what I've observed, it all tends to be a little bit more insecure, desperate, and dangerous than that in real life.
Additionally, Pirate Cinema is the exact opposite from Homeland on the realism front. The political situation in Pirate Cinema doesn't really resemble reality. In that book, people are getting thrown into prison for 5+ years for pirating movies? That's not real. That's not a real thing. That's never happened, has it? Because that's not real, the whole book has a weird straw man feel, since all the hacker kids are getting all worked up and self-righteous about an issue that doesn't exactly exist in real life.
Still, getting worked up about an imaginary problem is hardly a mortal wound for science fiction, and the book is still really fun, so there's that.