Personnally I wear only jerseys attached to an event I have participated in, club affiliation or something I have earned. I normally wear plain bike specific clothing with no logos etc.. However, it is up to the individual. Making fun is not mature and I would much rather ride with a mature individual with a postie Kit rather that someone that was acting childish. I respect a ride by 1) maturity and 2) riding or fitness capabilities and then 3) accomplishments.