Probably be better posting this in the equipment section as you will likely get more of a response.
In terms of image quality, a.f speed and build quality the 24-70 wins hand down no comparison. However it's more expensive and a heavier lens to carry around. The 24-85 f2.8-4 gets quite poor reviews it's supposed to be very soft at 2.8.
Depends what you want the lens for really, for me when I had the same decision to make it was no brainer to get the 24-70.
A better option if you need something cheaper than the 24-70 would be the older 28-70.