very good solution for amateur photographers - Addendum

Have before buying the Canon kit Obkjektiv used. The Canon 18-135 and the image stabilized Tamron 17-50 VC 2.8 I was able to test extensively.
As a result, provides the local model in my opinion the best mix of positive qualities and that too at a very fair price.
I would like to highlight the following points:

compared to the two used Canons:
+ Brighter
+ More sharply (over most of its focal length) -. In my experience, especially the Canon 18-135 is in no way associated with the imaging performance of Tamron zoom (ok, that might be unfair comparison because of significantly higher zoom range I mention it but anyway because maybe superior to other customers if you are sacrificing the image quality for the benefit of the more versatile focal length range. ME they should not, but to get even a telephoto rather at the earliest opportunity)
+ Sun visor included
+ Front element does not rotate, so that one can use well Polarizer (goes the 18-135 Canon but also good)

in relation to the Tamron 17-50 VC 2.8 (image stabilized)
+ Lighter - the stabilized Tamron is so heavy that you can already get some problems with the rather small handle a Canon 500D. I found anyway, the camera was with this Klopper no longer comfortable to hold
+ Sharper - is especially true in the corners and at 50mm over the entire image
+ Significantly cheaper
+ Filter thread does "67 mm" in diameter, which makes the filter buying cheaper
+ Autofocus goes mE a bit faster (may quite possibly be, however, also imagination)

Less great in my opinion, the autofocus motor. He could be quite a bit faster and quieter especially.
With the precision of the autofocus, I am satisfied, however, would say that the Canons were a little better here.
The build quality is decent, but not exhilarating.

As a result, I can recommend the lens fully. Who the money for allegedly even better Canon 17-55 2.8 does not have, or its enormous price simply does not want to pay, will find a very decent alternative that also considerably more compact and lighter comes in addition to the favorable price.

ADDENDUM TO 20,000 images and upgrade to Canon 550D:

The fact remains: The Tamron 17-50 non VC offers a hard to beat overall package of price and performance. From the close-up at 50mm to 17 at Panorama - always thrilled it with his super resolution with good contrast and decent color fidelity.
During my transition from the CANON 500D to the 550D is my Canon 55-250 IS "fallen by the wayside." It obviously comes with the enormous resolution of 18MP sensor simply no longer with. Not so the Tamron. Goods very good pictures with the 500D, the resolution a bit is now even times higher. For a zoom lens really a very, very strong performance!
If I had to decide again today, I would again choose the better sharpness and compactness of 17-50 non VC and let the newer 2.8 17-50 VC on the shelf. Its image stabilizer I ultimately rarely missed (eg in churches or other very dark rooms).
Since I photograph mainly for hiking, but I am looking practically every day on the relatively low weight and compact dimensions of the non-stabilized version.
With the processing, there has been also no problems.

The only thing I would wish for now, would be a quieter and faster autofocus. Here you have to remember the low price of the lens but again. As you can probably just a luxury so do not expect.
Anyway, it's great to just be able to get as much power as amateurs with a manageable cost.
And that's why there are of me later still the 5th star.
Anything else would simply quibble with the overall performance and the price.
Very strong buy recommendation!