Originally Posted by Mark Elberson
The Sigma is indeed very good according to a detailed review which I don't remember where I have seen it. It's slightly better than the Canon optically. Sigma these years seems to be very ambitious, their 50/1.4, 150/2.8 Macro, 24-70/2.8 HSM all seem to compete head to head with Canon and Nikon optics.
All I'm saying here is that I think Sigma does have a reason to sell their new 24-70 lens at such a price, but I agree with you - for that much money I'd rather get my 2nd copy of Canon 24-70L...