Ambrosio are one of the older more traditional manufacturers of rims in Italy and have been making them for decades.
Paul Hewitt has used the very slender Sapim Lazer butted spokes that can be specified with brass or weight-saving aluminium nipples. Spoke tension is both tight and consistent throughout the wheel and the threads are completely screwed into the nipples - both hallmarks of a properly built wheel. Indeed, both wheels stayed true throughout testing.
Shimano are resolute in their belief that ground cup and cone bearing races on the Ultegra hubs used here are better able to distribute radial and axial loads and who are we to argue? A great pair of wheels indeed.