Do a google...there are alot of "personal" opinions out there.
I believe the different camps ended up with bad batches which is why some saw the tamron images as flawed while other saw the same for the sigma. overall, I doubt I can see the difference in real life if I don't scrutinise the images with the a magnifying glass!
But personally for me also, the sigma lens look nicer. the gold rings on the tamron look so "uncle" for me (although I am an uncle myself..haha).
Frankly, as I said, it's all down to sample variation.
I suspect that if the manufacturing tolerences were tighter, the lenses would be uniformly excellent - indistinguishable sharpness to the nikon 18-200.
I think end user...like me using DSLR as P&S:embrass: and print not bigger than A4, both lense should be ok right ?:think:
true, i think a lot down to sample variation. better test before buying..