In LA Nami is actually what she suppose to be in manga by Nojiko words about her "never laughing" etc.
You can't make character that overall acting like she carring about people, always smiling etc and then said that actually she never laugh.
Nami in LA is actually what she suppose to be without gags. I feel that she will became same Nami as she was in manga before timeskip, but that will be her character growth.
Also God I hope that in LA Nami vs Dublefinger will be great fight, case in manga it was garbage.