Oh, and Garp is really funny in the anime. I liked the more serious version of him from the live action, but they showed way more of his similarity to Luffy in this and it got a few laughs out of me in quite a short space of time.
Just to expand on this, I can't see Live Action Garp doing the whole "oh yeah your father is a super dangerous criminal. Oh, uh, forget I said anything" gag. Or the "we're not going to capture you, because you're my grandson, and the marines will definitely be ok with that reason" gag.