It is my opinion that, depending on your regulator, you will probably almost always get criticized in someway, if there is no audit committee.
The level of critisism will depend of the size of your institution.
What we have found that works well for our bank, is that the audit committee meets an hour before the monthly board meeting. We have an executive assitant who is responsible for keeping all of the minutes (ALCO, Audit, Internal Loan, etc.) and all are subsequently approved by the BOD.