I have read a lot in this forum regarding this lens.
Thought it might be intersting too know - that here i Norway only a few shops now are selling this lens ? Why ? Because they had so many complaints about it used on Canon 20d.
I asked one of the shopowners - and he told me that its very sad it has been so - because - he said the Sigma 24-70mm 2,8 EX DG Macro is a very good lens. But - it has got so bad reputation that he felt he was not taken seriously as long as he had it for sale.
In norway we have between 20 and 25 serious netshops ( like B&H i NY ) that sold the ,ens - now only 4 is left selling it.
So far (touch wood) I've not had any problems with the lens.

