Originally posted by grispie He is actually pinpointing the biggest issue with this lens. Most people considering to buy this lens will ask themselves the same question, and that is including me.
I am certainly not asking that question.
The Tamron 17-50/2.8, which I have had for a couple of years now,
is too big and obtrusive for discreet use on the street.
It already attracts unwelcome attention from security wannabees,
and can intimidate some subjects.
The Sigma,which is 50% bigger and almost twice the weight,
is only going to be worse from that point of view.