You can hardly call these heavy at 1520g and the Pacenti SL23 rims is wide and stiff. The spokes in this build are Sapim CX-ray laced radial front and 2x rear. The hubs are the everlasting Dura Ace 9000 one of the best road hubs on the market. The wheels are very stiff meaning good power transfer but far more importantly the NDS rear spokes cannot go slack no matter how much power you put out. Rear wheels give problems if there is flex as flex fatigues spokes quite quickly.

So light and stiff kind of makes the perfect wheels and given the hubs are Dura Ace they will last a very long time indeed.