Although I wish I could keep that free rolling, 170g Ultremo feeling throughout all this, it isn't practical as there's so little to those tires in terms of protection, it's virtually guaranteeing flats.
Enter the Continental GP series. I've always had good luck with these, and a few layers of Vectran seem to work magic out in the real world. The 4 seasons 28mm tire is only 260g, which for what it offers, sure isn't much.
Now that Enve has pressure gradient rated their XC rims, I'm exploring the possibilities. The 28mm GP 4 Seasons, when installed, is almost exactly the width of the rim itself. It's such a clean looking profile that way. 28mm tires are allowed up to 100psi, I've gone at 90 just for some comfort, as I'm not a fan of rock hard pressures overall.
On a little test ride, they soak up the road very nicely, and give a lot of contact with the ground. They feel secure. Their 260g doesn't spin up too poorly either. If it can do duty at Paris Roubaix, it sure can work around here!