I tried reading Evil Genius for the first time a couple of years ago because I thought that it would give me and Artemis Fowl-type fix, but I just couldn't get into it, but I actually quite enjoyed it this second time around. My mistake was probably picking it up and expecting something like Artemis Fowl, and who wouldn't, since it's about another boy genius who uses his intellect for crime, at least initially, instead of for the greater good.
Unlike the Artemis Fowl Series, Evil Genius is written for a slightly older reader, and quite long, weighing in at nearly 500 pages with small print. Although the story became sluggish in the middle, it soon picked up, and I raced to finish it.
Katherine Jinks spends time developing Cadel Drakkon's social, emotional, and mental profile (probably a contributing factor to the novel's length ;) to create a three dimensional character while still including all the suspense you'd find in a spy/chase/crime novel, and including tidbits of computer science and mathematics. Evil Genius contains not only the internal struggles of a misfit boy who has been mistreated, but also includes quirky comedy through Cadel's observations of his crazy teachers of crime.