Shag rock is nice and easy, very relaxing spot... Have you done the pass-though under the big boulder?I am there as we speak haha. Manta bommie has been out due to the current. Did two dives at shag Rock though. Hmas brisbane was due to weather conditions, so I booked further north at rainbow so now I am committed and don't want to backtrack South due to overall trip time constraints.
Good luck with Rainbow: i hope the conditions will get better!