Overall I'm very impressed by what they were able to do in eight episodes. Arlong Park could have been a bit better (though Arlong himself was fantastic), as could have the Shanks/Mihawk meeting which was far better in the anime. But AP at least probably suffers a bit from them having to go from 10 to 8.
One thing I liked a lot was how the wanted posters waft in front of the pirates and get moved away. Krieg being massively scaled down was great because that all sucks anyway. Syrup could have done with that too but it's intrinsic to Ussop's story so what they did was about as much as you could (poor Merry though...). Luffy's line comparing Shanks and Zeff made me laugh. Loved Bogard having a bigger role, all the extended stuff with the Marines was very good.
Very enjoyable show and I hope it avoids the dreaded algorithm cull.