Recommend me a lens (Nikon) Sigma 18-50 vs Tamron 17-50.. help

[jamin100]

Im looking to buy a new lens for my Nikon D90.
I currently have a 50mm f1.8, Tamron 28-75 f2.8 and Sigma 70-200 f2.8

I mainly take photos of my children running here there and everywhere!

I'm contemplating selling/trading my 28-75 for Pheraps a Tamron 17-50 but wondered if anyone had any other suggestions?

My budget is very little, It will be whatever I can get for the tamron + maybe £50-£60 for the right lens.

I'm defiantly looking at 2nd hand but want something fairly fast to focus and good IQ.

Can you suggest anything other than the 17-50?

If not, how do you rate the tamron 17-50?

EDIT:::::

Ok, looking at my budget etc I think my only options are:

Tamron 17-50 f2.8 (Non-VC, No Motor)
OR
Sigma 18-50 EX DG HSM f2.8

 

[cambsno]

Do u need wider? If so get the 17-50. If not then stay as you are as u will get nothing better for that budget.

 

[jamin100]

Do u need wider? If so get the 17-50. If not then stay as you are as u will get nothing better for that budget.

Yes I think i kind of do.
It was my daughters 2nd Birthday yesterday and because it was a miserable day we were all inside. I found the 28mm of the tamron too long for most shots.

 

[Dave in Wales]

Nikkor 16-85

D in W

 

[desantnik]

Tamron 17-50 is great optically but slow focusing. Not usable for high speed children in any consistent way.

 

[jamin100]

Tamron 17-50 is great optically but slow focusing. Not usable for high speed children in any consistent way.

Yes i have been reading that this morning.
I'm also considering the Sigma 17-50 as thats a 2.8 lens but also has HSM

 

[desantnik]

I have the Sigma 18-50, its quicker than the Tamron, but not stellar.

The Nikon 17-55 is the king in this area, that will do it, but its more than twice the price...

 

[jamin100]

Ok, looking at my budget etc I think my only options are:

Tamron 17-50 f2.8 (Non-VC, No Motor)
OR
Sigma 18-50 EX DG HSM f2.8

Research. . . . .