Umm...how about the obvious ones: RS no traction control. RX 21 level traction control. RX makes both more hp and tq. Much nicer gauges/readout. Then there's this, "The 1190RX builds off the RS model, but EBR claims development of 426 different parts for its latest offering." It's all a progression. EBR made the RS on a shoestring budget, they were tiny and it was their first bike. The RX has another 2 years of racing, development, and research behind it. Not to mention a much bigger development budget due to dollars from Hero. I understand that the RS has high end components and was had built, but to say the RX has no improvements is well...incorrect.