I would absolutely not put the Hotel Arts below the Intercon in Barcelona. Depends which RC you mean in DC, the M street RC is > IC. Haven't stayed at the others or the Osaka property. I can't think of any city that has a RC and an IC in which I would choose the IC. In general RC are a half step or so behind most but not all FS properties. Have never stayed at a Regent, seems like an odd off brand property.