Nikon 18-200 vs Tamron 17-50

Hi all.

Help me out here please.

A couple of months ago i sold my Nikon 18-70 and upgraded to the nikon 18-200. But i am not very impressed with image quality on this lens. Sure, it a very versatile lens but thats all. It creeps and is very slow.

So i am considering to sell it and get the Tamron 17-50mm 2.8.
Is the Tamron Sharper than the Nikon 18-200???

I don't mind the gap from 50-200mm since i already have a 80-200 f2.8. (which i love)

Thanks.

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Lars
Nikon D200,SB800,SB600
Nikon AF-D80-200mm, AF-S105mmVR, AF-D50mm, AF-S18-200mmVR
Sigma 10-20mm