These events are nothing but a hustle.
Yes they will tell you how to be more competitive, but going to these events do NOT actually change any metrics that would increase your chances of getting hired....I have been told this by 2 different airlines (HR people that actually do the work) that use Pilot Credentials.....all they can do is search the database with given parameters.
These fairs ARE a game changer for many of the smaller operators that use more traditional selection methods.