To be perfectly honest with you, the "cons" list for this novel is extremely limited. We came up with "heartless euthanizing of babies and elderly" and "leaves you with an icky, paranoid feeling". But when have these things ever stopped a young adult from reading (and loving) a novel? The sheer creepiness of Jonas' society—and how eerily similar to our own some of it is—draws readers like flies to honey.
The real difficulty lies with the shock and denial a young, inexperienced reader might feel about the unhappy bits in the book. Imagine watching the nightly news and reaching total saturation when you've heard about the hundredth natural disaster or unnecessary death. You switch to a comedy or pay more attention to the ticker running along at the bottom of the screen—or you turn off the tube. Either way, you don't need any more details. For students who are unaccustomed to the nastiness lying very near the surface in dystopian/utopian literature, the need to tune out ugliness means that they might miss some very important concepts: "releasing" means death, taking a little pill means never feeling...anything. Keep on the alert for students in high avoidance mode by asking for a summary every now and again. You never know...it might provide some comic relief!