This is a very well built lens, feels solid and is actually a little heavy. There are no complaints regarding the processing quality. Optically the lens really suffers at 10mm as the quality around the corners isn't what I think is optimal. While it's true that you can set focus to infinity for ultra-wide-angle lenses, that's not always the case when shooting indoors, and not being able to know I've got perfect focus is a real disadvantage. I would definitely spend a few bucks more and get a Sony 12-24mm or Sigma 14-24mm for my a7riii. I just can't afford to be uncertain about focus (focus peaking helps, but it's not infallible).