Last year I purchased aTamron 24-70 f2.8 and the pictures always send soft. Tried the at adjust on my camera and it helped, but not enough. Paid the shipping to send it in and they said there was a servo error. They replaced it under warranty, calibrated it for my camera, returned it and I have been happy with it since. So to sum all of that up, yes, I would still buy a Tamron lens again.

The Nikon 24-70 is a beast. As others have said, it's not about what others saying it needs to be your go to, but you'll find that it's the one you will go to. You could go to a local camera store and check out other brands version of the same thing. I'm running Tamron's 24-75 f2.8 on my D7100 (DX body) and it's small and light. It basically lives on my camera.

The sponge is actually more like an ultra-fine sand paper. Had a friend use it to clean a few spots off his car. Next wash you could see where it basically sanded the clear coat surface. So camera body, sure if it were really bad, but never on glass or screen.