My only DX lens is an old Sigma 18-125 so I started to look for premium quality all purpose standard zoomHere is what I found from DxO mark, contradictory to my buddy shooterhttp://www.dxomark.com/index.php/Lenses/Compare-Camera-Lenses/Compare-lenses/(lens1)/498/(brand)/Tamron/(camera1)/680/(lens2)/173/(brand2)/Nikkor/(camera2)/680/(lens3)/377/(brand3)/Sigma/(camera3)/680Any comments

You mean the 17~55? It might help if you fix the title.I would get one of the more modern lenses, specifically the Sigma. I don't think DXO Mark is necesarily the best way to decide because there is so much to consider that they don't. Build qulaity would be one example, and maybe that would take you back to the 17~55. Personally the smaller size and lighter weight of the Sigma make it appeal more to me, and you won't really find that addressed by DXO Mark either.