Canon 24-105 vs Tamron 24-70

How would you all compare the Canon EF 24-105mm F4L IS USM versus the Tamron 24-70 f2.8 VC?

I'm trying to decide whether to get the 5D MkIII with the Kit 24-105 or the body only and get the Tamron 24-70. I wish the 24-70II was out, I'd probably get that, but in the mean time, what would you all suggest?

I'm definitely getting the Canon 70-200II and the 16-35 as well.

Thanks