The only factual difference would be the moderation: Mods in reddit are too trigger-happy, that changes user behavior; it makes everyone act like cattle in order to conform to their bullshit standards. Updoots and medals don't matter that much, it just reinforces the shitty attitude.
4chinz? Unless you're a /pol/ or /a/ mod, no one gives an absolute fuck about the rules. Do whatever. That's why this site is "better"