I was with HC-4 (NAS Sigonella) when we turned in our CH-53Es, for further transfer to the USMC, and we transitioned to MH-53Es in the mid-90s. Aircraft are completely similar for the logistics role, other than the fuel capacity (20K for the MH and 15k for the CH) and a few odd items associated with the towing mission which we removed. Can't speak for the all the avionic upgrades since, but flying wise they were identical, other than a slight little extra bubble of air on final touchdown caused by the larger MH sponsons. For the RAG mission, shouldn't make any difference.