The Diverge (carbon frame) is out of my price bracket. And what's the problem with 28C? For me they would be as fast as a 25C, but deliver more comfort.
28c tires are heavier, less aerodynamic and contrary to baloney espoused on the 41 by a limited few, have higher rolling resistance than 25c or 23c tires. There is a reason why the top racing bikes sold by best makers do not come with 28c tires. Many in fact will not fit 28c tires. If 28c tires were faster, the fastest road bikes sold would come standard with them.