I have the '02/'03 Zondas, which are nearly identical to the Euruses, at least the rear wheel is except for the steel pawl. They're great wheels, but the only complaint I have with them is the same as with almost every other wheelset: the rear can be seen to be out of balance when it's spun up to high speed in the big ring. I've heard the same thing from a friend who owns Eurus'. They're not terribly out of balance, but it is easily noticeable.
The Fulcrums supposedly correct that with their rim machining to make the wheels balanced. I'm surprised that no one has really thought of that before as a selling point.
OTOH, the Fulcrum rims are "only" 26mm in depth, so not much aero benefit there. Then again, who knows if the 30mm rim depth of Zonda/Eurus makes much difference?
I wish Campy/Fulcrum would have had a more unique design in the case of the Racing 1, instead of a rip-off of the K's. But they have to consider market forces, and what will sell the best.