It depends on the jurisdiction. My state doesn't recognize ICC certifications. The state runs its own pre-licensure classes, administers its own tests, issues its own licenses, and conducts its own [required] in-service training classes.
Other than having to have the required state license, what I would look at would be experience. The department I just left currently has a chief BO who prior to that position had about one year as a residential inspector in a much less busy town, and three assistant building officials ALL of whom had just passed the licensure exam and none of whom had any previous experience. Since my departure, there is nobody in the department who knows how to review plans under the IBC or the IEBC, and nobody with any experience inspecting anything other than single-family residences.
It's a recipe for disaster.