This weekend's episode of One Piece spent a lot of time setting the stage for the rest of the arc, but it mixed in enough action and wacky gags to keep the flow moving smoothly.
The shouting matches between Buggy and Luffy were great fun in the early episodes of the series, and now that they're forced to be on the same side, they make a solid comedy team even while Buggy still treats Luffy like an enemy. One of the best parts of about Buggy's return, though, is how he can see just how much Luffy has grown in the last ten years of One Piece. A lot has happened while Buggy has been off-screen languishing in prison, and he reminds you of how different Luffy is from that boy in a barrel from episode 1.
Even though Luffy can take down an Impel Down guard in one punch, though, he's not THAT different from before - he still has the ability to make friends out of anyone, and his unthinking generosity gets Buggy over to his side quickly.
In other threads, you get to see a lot of the story of Impel Down itself - it's not just a dungeon set piece, it's a well-thought-out setting filled with its own life and color, like all of One Piece's other great locales. Buggy's quick escape from Level 1 of Impel Down gives you a lot of scenery and story in just a few shots, and the imagination that went into each piece of the setting makes you excited to see the ever-crueler levels of Impel Down!
Next week we get to see the main antagonist of the arc, the warden Magellan. It'd be good to have some proper villains again, as this current storyline could use a lot more conflict before it kicks into high gear.