Sigma 24-70 sent back

Got a Sigma 24-70 IF EG DG for my A57 and A65.
Talk about slow focus.....
I could have run quicker.
Got it today...sending it back today.

The standard little zoom lens that came with the cameras (18-55) is lightning fast focus , and most probably sharper.

George

Any suggestions...or are all the Sigmas like this.
Might try Tamron.
We battle on.