Hi all, I'm thinking of upgrading my Pentax 18-55 lens on my Pentax k10 for a Sigma 17-70. I've seen it online for £229.99 with a free Hoya uv filter. Is this a good upgrade lense, or are there any better options around this price range? 

I have the Sigma 17-70 on my Canon and I think that it is a great lens for the money. It suits my type of photography and is my walk-about lens. There is lots of discussion on various forums about filters and whether to use them or not, I am in the not camp, why put a cheap bit of glass in front of an expensive lens? Digital does not need a UV filter. Back to the lens remember it is not 2.8 all the way through, the macro facility is useful but not 1:1, I find it focuses quickly and quietly on my camera and would rate it 9/10.