I'm finally done with Water 7 in One Piece, and I enjoyed it quite a bit! Granted it feels like an intro to Enies Lobby, but it has many great moments to call it's own. Some thoughts:
The fight between Luffy and Usopp was genuinely emotional, and if I didn't already know they make up in the future, I may have thought that was the end of Usopp being a straw hat. I also think Rob Lucci has the makings of a great villain, assuming he gets more development in Enies Lobby. The reveal that he and the rest of the ship-builders (excluding Paulie) were CP9 wasn't a huge 'wow' moment for me, but I can't say I expected it either.
Now onto the real arc, Enies Lobby!