I'm running them. I have the Campy Shamal wheels that allow me to run tubed or tubeless. The ride quality of the Hutchinson Fusion 3s is phenomenal, but so is the price. Retail for around 100 bucks a tire. If you shop around, about the best deal you'll find is low 70s. I rotate mine every 700 to 1000 miles and usually get about 2500-3000 miles out of a set. These are the only tires I have ran. I'm not sure how some of the others compare.
But, mounting them used to be a huge pain. I say used to be, because the Prestalevers have made it much easier. See my review of the
levers here. I highly recommend getting some if you go tubeless.
I still carry a tube with me out on the road, and if I flat the tubeless, I simply install the tube and ride home. I've had two flats in about 6000 miles on the tubeless. One was a hard hit to the sidewall, and the other was on a tire that I really should have changed already.
Let me know any other specific questions you might have.