YMMV / Spy School

• Ensemble Dark Horse:
  • Bjorn, the identical cousin and Good Counterpart of recurring villain Dane Brammage, and Affably Evil drug lord El Diablo have good fanbases despite only appearing in the ninth book so far.
  • Wilderness survival trainer Woodchuck Wallace has only been involved in a handful of missions but is one of the more interesting non-main adult characters.
  • Ashley and Nefarious, Ben's fellow students at the eponymous Evil Spy School, only appear occasionally and in lesser roles since the third book but are some of the best-liked SPYDER members.
• Harsher in Hindsight:
  • A whole strew of these moments comes from all of the Butt-Monkey, All Love Is Unrequited, The Friend Nobody Likes moments Warren gets for the first four books. He gets fed up enough to defect to SPYDER.
  • In the third book there's a scene where Zoe is used to feed the CIA information about Ben and Erica after they've supposedly defected, to get them to raid the villains lair. Ben (earnestly) thanks her for "betraying" him, and she shows up in the raid saying she got to come as a reward for ratting him out. Come the eighth book, Zoe really does betray Ben and Erica when she's convinced that they really are traitors (or rather that Erica is and that she's manipulating Ben) after initially seeming to still believe Erica and gets rewarded for this with a promotion (to her own slight discomfort).
• Love to Hate:Murray Hill may be a petty and immature Dirty Coward with a Chronic Back Stabbing Disorder, but his hilarious dialogue and The Chessmaster ploys keep him entertaining.
• Moral Event Horizon: Cyrus Hale embodies Good Is Not Nice for books 2-10, but it becomes a lot harder for either the readers or the characters to view him as a good guy after the last act of Spy School Goes North, when, due to little more than Control Freak pride, he is willing to let a Russian plan to blow up the oil at the Arctic National Wildlife Refuge go forward, and even tries to interfere with the kids' attempt to stop this. Said plan would kill hundreds of people and countless endangered animals and amp up climate change exponentially overnight.
• Sophomore Slump: Spy Camp, the second book, is often seen as doing less with the characters, setting, and worldbuilding than either the first book or Evil Spy School and Spy Ski School, the two after it (both of which sometimes get seen as Even Better Sequels to the first installment).

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