Paranoia has long been one of my favorite role playing games, and the XP version captures flawlessly and yet updates the storyline to make it match the modern era. There's a lot of revamping which just makes me drool with excitement, such as the breaking down of the service groups into sub-groups; the addition of a link between service groups and the secret societies, and even the rules on a "more serious" campaign.
That being said, there are quite a few flaws in the system. (Which, this being Paranoia, is probably appropriate.)
Biggest, to me at least, is the fact that the "Sample Conversations" and the like are pulled directly from 2nd edition. Verbatem. Despite the updates to the secret societies and service groups. Which means they no longer truly serve as examples.
The second is more of a complaint with the eBook, but there's no table of contents or other hyperlinks. At $25, it's not necessarily at enough of a discount to accept a pretty lazy scan-and-sell. Look at Pathfinder from Paizo Publishing - the Core Rulebook is $50 in hardcopy, but the PDF version is $10, and provided both a black and white and full color copy, providing extremely detailed hotlinks. It's "If you didn't want to support the electronic version, why'd you sell the electronic version."
The final issue has to do with the layout as well, although this suits both versions. Again, the layout feels a lot like the Second edition, with tightly laid out columns. Or, to put it another way, "in hard to read columns." Since it's a secure PDF, I don't have the luxury of exporting it to text or anything like that, so it's really bad for the eBook, but I'm guessing it's not much better with the hardcopy.
Still, I'm happy with the XP version of the rules. So, keep your PDC on silent and free of Secret Society apps; hide your Machine Empathy mutation, and of course... stay alert, trust no one, and keep your lazer handy.