Here is the Tamron on the Nikon.
http://www.photozone.de/nikon--nikkor-aps-c-lens-tests/290-tamron-af-17-50mm-f28...
Like I said it's on a Nikon but it's the same lens and Nikon is pretty close to Pentax so you can make a fair comparison I believe.
Keep in mind the numbers are differend in the graphs

Like mike said, the kit-lens is also a pretty good lens but the extra reach of a 17-70 would make it an perfect walk about lens in my eyes.
There isn't much difference between Pentax and Sigma, simply try them out in the shop to see how they handel and look at the photos on Photozone to compare bokeh, colours and contrast.

I would sent it back to the shop then if I were you.

The K20D has an even larger buffer so if you don't shoot more then 14 frames in one go you wouldn't really notice the difference.
You can notice it when reading the card, it simply takes longer.

Most of the time SRS is cheaper and you get free delivery as a Pentaxuser member, so there really isn't a big difference if there would be one.

BTW Carl where did you find out about the discount, this the first time I hear about that one

ps. Kris the TC works like a dream, will upload some photos if I make any good ones

Thank you Ian, I've heared good things about it but I already have the D-FA 100mm so it would be a waste to get the Tamron 90mm and 10mm doesn't really make a difference at that range.
Also money is a problem now after buying the 50-135 (I'm a poor student) so need to sell the 18-250 and get a POL for the 50-135 first.

And I'm selling my 18-250, it's quite personal with type of lens you would use. Some use the 16-50 for portrait while others 50-135 or prime lenses.

If panoramas, portraits and street photograhpy are your main interests, then the 17-70 would be an better choice. 17mm is usable for panoramas and lanscapes, and the 70mm is perfect for portraits.
The 18-250 will also cover that range of course but because it tries do to everything it's not really as good as the more specialize lenses so that's for you to decide.

The 55-300 is also a perfect lens to start with, if you also get a Pentax A 50mm 1.7 from ebay you'll have a kit to experiment with to find your liking.

Well thank you Ken
Yes it makes perfect sence, I was also questioning to leave the sharpning up or not mainly because of the tree but the darken layer makes up for most of it.
I like how you could keep the mist in there and boost that, it's quite hard since it effects the whole image.

Yes... well atleast B+W still have them on their website I believe.

Well I just ordered the DA*50-135 at SRS.
This is the perfect range for my style of shooting in the studio and now just hoping it will do good enough for the stage.
If I still consider myself in the need for a faster lens I'll buy a second hand 50mm, it will preform good enough for the stage.
Maybe I will even sell the DA40 also and get an FA43 instead for that purpose

They're all wonderfull but the close up of the seal is my favourite.