Anyone out there using 5D3 + new Tamron 24-70/2.8 combo?

I took the risk and ordered this new Tamron 24-70mm/2.8 ...VC... (Tamron's IS). Received it yesterday and tested it on a barbecue. Mechanically and optically quite a nice standard zoom - given it's competitive price. First I had to microadjust a heavy frontfocus with lenscal, same with my 7D. But during the barbecue I lost my good mood: my 5D3 with its stellar AF performance with Canon's L glass (e.g. my 70-200/2.8 II) really struggled with the Tamron resulting in loud, nasty rattling focus hunting (different AF settings didn't change anything). Finally I gave up shooting quickly moving children, but even static portraits resulted in 2 of 3 out-of-focus shots. I am completely frustrated with this Tamron as it basically is capable of producing wonderful pictures with quite a nice bokeh (9 blades produce nice round OOF spots in background) if it does what you want, see example here:

Is there anyone using the same 5D3/Tamron combo? I'd appreciate your comments.

I may have gotten a bad copy, Tamron is commonly known for an easy going production end control. So I'll return this one and give Tamron a second chance. Otherwise I go for Canon's new 24-70, which is quit a different bang in the budget.

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Picturenaut