I'm hoping the Aria & spa veterans can help me out. Is there much need to pre-book spa before arrival or is it something I could do while there? I'm staying Sunday - Friday. I did pre-book something at the Mandarin Oriental spa for Friday but only because it was really important to fit it in before my flight Also - any recommended treatments? I was looking at the classic massage (maybe with the green tea eye compress) and/or gemstone facial.