It doesn't really seem like Corsair has done much to justify the price premium here. I suppose if one is into RGB and the iCue ecosystem it might make sense. I do think it's a shame they've gotten to the point where they charge more because they're Corsair though as the products aren't bad.
I could see tying the pump to the coolant temperature for variable rate pump speed, but definitely not the fans.
While the fan add on is the most interesting to me of what they have available it just increases an already high price. To me this is made worse due to Arctic having VRM fans with their entire line and Silverstone has the IceMyst.