For one thing, you won't be able to touch a V8 Challenger right now and if you could, expect to pay big $$$ in dealer gouging. Don't see the hype myself. Same as the Charger really, just a 2 door and a slightly shorter chassis.
Though I like my Magnum, if I were in the market for a new sedan would I buy a Charger or a 300? No. Hate to say it, but I'd take a Pontiac G8 over it. Think you can actually get them cheaper even.