It does seem amazing that none of the dozens of manufacturers are getting it quite right. We want a waterproof jacket with real vents, not vents that are blocked by a waterproof membrane, but vents that open all the way through. And we want them on the arms, back and chest. The Horizon seems to have gotten closer than anybody so far, but there's still room for improvement.
One thing that puzzles me about the horizon is the zippers under the flaps of the main front pockets. My Sand jacket doesn't have them but the pockets are still waterproof. Why add zippers that add cost and make it more difficult to get into the pockets? Sometimes I think Revit throws away good ideas just to be different on the newer design. Anyway, I may still give the Horizon a try. It may be worth being hot sometimes on long trips, for the convenience of being waterproof without a liner.