I also have the Sig 180 and the Tamron 180, I prefer the Tamy for weight difference easier to hand hold and it has the same IQ as the Sig.
gorgehiker wrote:
I bought a used Sigma 180 2.8 Macro lens and it is so great that I almost never use my Nikon 105 2.8 anymore. The Sigma is a big heavy beast, but I love it! On a crop sensor camera, I it is a 270 Macro!