Sigma 17-50m a good kit lens upgrade?

Im looking at an upgrade for my 18-55mm kit lens for landscapes and 'people' photography as I now have a little one so I want some wider with a wider aperture so I can use it in lower light levels for the odd gig too.

The sigma 17-50mm looks like a good fit at a decent price, but do you have any advice or other options I should consider? Would rather not splash out too much more than the £300ish for the sigma, but may be persuaded to go a bit higher if the increase in quality is good enough!

i believe the Tamron 17-50 f2.8 seems to be well liked by users and could be cheaper than the Sigma. after saying this there is a Sigma in the classifieds forum for an excellent price at the moment

I have the 17-50 it is a really nice lens, it also fits in nicely with the 10-20 zoom, like most of that range of Sigma lenses it just feels right to me....I had the Pentax 16-50 DA* but I didn't really get on with it, the sigma felt much nicer to use, with no discernible difference in my results...

There is a nice one up for sale in the classified section for £180, so go grab yourself a nice sigma

https://www.pentaxuser.com/forum/topic/fs---six-lenses-including-da-fisheye-10--...

If you want just that little bit more then the Sigma 17-70 f2.8/f4 is a cracker. I love mine and it stays on my K3ii all the time. The K3 has the happy snapper 18-250.
CHEERS Vic.

Agree, but the Tamron 17-50 is a cracker, there is one in the Classifield forum too.

I just posted my almost brand new Tamron in classifieds, used once then purchase of DA* 16-50 meant a life on the shelf for the Tamron.

I agree with the comments regarding the sigma 17-70. I bought it as a walkabout lens for my K3II and have been very pleased so far.

my Sigma 17-70 was fine and giving very good results but it developed a fault which i believe could be the OS system, when zooming in or out at around the 24 mm point the image will jump diagonally across the view finder and something is very loose inside. never been dropped or harshly treated and have had it around 18 months.
not worth the repair cost at Sigma prices so purchased the Pentax 17-70 f4 from a forum member, anther that would suit the OP

I do not think that you would be disappointed with the Sigma 17-50 which DXO found to be the sharpest lens tested with K5 and K3. I was delighted with the results. The Tamron equivalent is also pretty sharp but the copy I got was slightly decentered and once I saw the distortion on one side, my eye was always drawn to it. The Sigma is on the heavy side and not WR. Last year I bought the Pentax 16-85 for its greater reach and WR capability and I have found this lens also to be very sharp. I parted with my Sigma 17-50 with heavy heart as it in part duplicated the focal length of the 16-85 and I needed a contribution towards the cost of a K1, but I would happily have kept it and returning to your question is a considerable step up from the kit lens.

http://www.pentaxforums.com/reviews/pentax-16-50-vs-sigma-tamron-17-50mm/introdu...

Have you read this. The Sigma has dropped considerably in price since. I love mine

Thanks all. Went for the Sigma in the end. NOW I will buy no more lenses....