I am confused by the OP's first post, as it puts both A Club and Advantage Plus together.

From what I understand, A Club is free, Advantage Plus has annual due.

I guess the safer approach is to not worry about the A Club and just pay the higher rate (in Sydney it is 79 vs 71).

It seems most Accor properties, with exception of Sofitel and some Novotel, generally have mediocre reviews on tripadvisor. But saving money is important on a 6 week trip, so I will take the plunge.