Granted, at times, Tony is evil personified. But at least he shows some signs of affection and consideration (usually to animals more so than people).
But Christopher is in league with Janice and Livia in terms of being a cold, heartless creature.
He sold out Ade to Tony, not because of his loyalty to Tony, but because he couldn't bear giving up his money, power, and status. He saw that family at the gas station driving around in an average car, wearing average clothing, etc. He also saw that the guy's wife was heavy-set, and probably figured that Ade would become that way, especially by undergoing the treatment for her illness.
Ade loved Christopher so much and would do anything for him, but to her she was just a hot trophy girl so he could impress the world.
Tony would've never done that to Carm if he were in that situation.
I don't know if this specifically makes Chris "worse" than Tony, but you're spot-on about his motivation for giving up Ade. Chris' central character trait is, essentially, his view of mob life as a movie, and his desire to live as a movie character. He mirrored Henry Hill from Goodfellas when Ade first confessed to him, but the gas station scene showed him what Goodfellas doesn't show you - the boring, mundane, stressful day to day life of a civilian. that's the one thing Chris could never handle, though ironically his life as a mobster is still full of stress, repetition and ennui. He thought he could deal with getting noodles and ketchup instead of pasta, but the reality of civilian life, and life in general, really never hit him until that moment. Chris' preoccupation with movies and a cinematic lifestyle seems to stem from the idealized, hyperbolic stories he always heard about his hitman father, a figure he never knew, who is held over his head as the unrealistic standard he must aspire to.
Taps, lights out, 2200 hours. What's missing? Give up? Television.