[Brightcolours]

The Sigma 24-105mm is now my most used lens on Nikon D750. (I usually shoot lightweight f/1.8 native primes.)  

 

I get great results wide open. Sharp and beautiful. 

 

What swayed me to try it was a particular DXO measurement that I find extremely helpful: sharpness, "field" which shows you the sharpness across the entire frame at a given FL and aperture. The Sigma is sharp (green) across the board wide open. By contrast the Nikon 24-120mm was NOT, and in particular, it was very weak around 85mm wide open, which is an important FL for me. (DXO measured the Sigma on Canon bodies but the sharpness measurement turned out yo be a good indicator for my Nikon.)

 

It is worth the weight IMHO. 

DXO doesn't give reliable info. There are many instances where their "data" is obvious nonsense. And on their "field" map showing sharpness across the frame: It doesn't. They only "measure" 3 data points. and the whole colour map gets interpolated and rotated to produce that "graph".

 

Non the less, happy to read you are happy with your Sigma. For its type it appears to be a nice lens indeed.