Writing this at 11,600' elevation high in the mountains, with a cell signal.
The Sigma 120-300mm f/2.8 DG OS HSM S is impressively well built with a metal (!) lens hood, apparently metal body with a finish I rate more attractive than Canon or Nikon 300/2.8 designs. It is one of the new top-line lenses like the impressive Sigma 35/1.4 DG HSM.
The optics so far appear to be first rate: what better test than demanding razor sharpness into the corners wide open on stars? I really like having the zoom range over a fixed 300mm.
I’ll have review coverage in DAP upon my return.