Looking at where the OP is based, I don't think the RCC is a good deal for them. SQ leaves out of B and shares the lounge with SAS, whereas the RCC is in A. An RCC membership would only be useful to the OP if they arrive in to EWR on UA (which as the profile suggest they are based in EWR), as that security checkpoint would most likely refuse to allow them to pass with a flight out of B. Further, given the choice between an RCC or a CO President's club, I would take the President's club 9 times out of 10, especially if I had to clear security again anyways.