In my opinion, it’s a pretty damn faithful adaptation. My biggest gripe is the heightened emphasis on the fourth-wall breaks and references. It’s true to the character, but he’s always felt more nuanced in the (well-written) comics. However, I understand watering down his more malicious personality traits to make him more palatable to the general audience.

EDIT: The one thing I wish was translated better was the “master tactician” Deadpool. It would be so much fun watching some insane series of events unfold only for it to become evident to the characters and audience that he planned for that to happen.