I hadn't been to a Hard Rock anything since I was a kid. But the sleek, all-suite tower of the Hard Rock Hotel in Las Vegas is a far cry from the burgers-and-guitars brand that once existed. Inside, the gorgeous Reliquary Spa is proof that Sin City can be as relaxing as it is stimulating. I was invited there for a complimentary treatment and was stunned by the luxurious space that awaited. Here's my report.