Stay away from Tamron(24-70 f/2.8)

My Sigma 70-200 is an amazing lens. I would never give it up. I also have a Sigma 8-16 which I haven't had a chance to use much but it takes great pictures. Reviews for both the lenses were positive. Tamron 24-70 VR has been getting so so reviews and $500 for VR over the Sigma's 24-70 price seems ridiculous. So I will be getting a third Sigma pretty soon. Every brand has good and bad lenses. I can't speak for lenses I haven't tried, but the two Sigmas I have are fantastic. Things change and if you're not willing to be open minded that's your problem. There are plenty of car manufacturers that used to make garbage cars too and now make great cars. There is a learning curve for everything. Nikon/Canon didn't make great products from day 1. There is a reason why they had to make version II of some of their 'great' lenses.