@Jadosra:
Franky is like… "You can call me Aniki" and "Missy" at Nami, and that's about it.
Franky hasn't interacted much with Nami, but he's had a LOT of time and good interaction with Usopp making stuff, (in the anime filler especially) just hanging out with Robin, and dancing with Chopper at a party, etc etc. He just hasn't had as much time to interact yet, compared to say, Zoro and Sanji.
Brook is a little better, which is ironic, because he came later, but I still don't feel the same level of interaction I felt when Robin joined and when Chopper joined, for example.
Brook has had even less time., He was only oficially part of the crew for like, 10 chapters before the seperation. And its odd that you say that, since Chopper and Robin felt akward in the cast to me when THEY joined.
@Greg:
When you started reading OP, was Franky a member yet?
I ask this because I've noticed in readers that picked up mid-way, they have a difficult time accepting crew members they didn't know about when they started reading.
Yup. I agree on this, and as noted, Robin felt out of place to me for a long time… and I was sure when I originally saw images of Chopper that he was going to ruin the 5 member crew dynamic... (I originally caught up to the series in mid skypedia) they're natural biases built against something new and different to the formula... but if you see cast pics that have Franky in them and then watch OP for the first time, THEN you find yourself asking "when's that guy going to join?" as opposed to "whats THAT guy doing joining?" and its a very different mindset.
It applies to any series when new characters join a cast later. Riley in season 4 of Buffy was a terrible character, Angela always felt out of place on Gargoyles, Captain Lochley felt out of place on Babylon 5 compared to Ivonova,, and Gizmoduck and BubbaDuck were always akward in Ducktales. (For that matter Webby was out of place too even though she was in the first episode, she was added for the sake of adding a girl to the original comics and she always felt tacked on) Its natural for a change in character dynamics to feel strange without time to adjust to it or for them to get lots of interaction time with others.
Especially in OP's case where the cast is always expanding, but at the same time, there was a massive 220 chapter, 5 year divide between new characters joining. (Skpedia and Water 7 were both crazy long.)