Review: Tamron SP AF 17-50mm f2.8 XR Di II VC LD IF (Canon mount)

I always waited for a (good) review on this lens (for canon mount) before I bought it,
now that I have it, why not make one on my own?

So here it is.

This lens meets the expectations. It features (like the non-VC version) a very good image quality, combined with an effective image-stabilization.
The Vibration Compensation begins its work directly after pushing the trigger half trough, just like the Auto Focus does. So the image should be stabilized right when the AF focused the motive. There is no 1 second delay before the VC-mechanism starts working. (At least in the Canon-mount)

With F2.8, 17mm at the wide end and a very good image-stabilizer, the lens is well-suited for available-light- and indoor-photography, as well as for every other situation with challenging light conditions.

Overall/haptics:
The lens looks nearly exactly like the Tamron 18-270VC, except that it is about half an inch shorter. It also uses the same 72mm filters. It feels solid and for the short length also a little bit heavy. The zoom ring turns to the right and has a convenient drag. All in all, pleasant.

Focus:
I experienced the AF to be fast and accurate. Due to the fact that the focus ring only rotates about 45 degrees, MF is a little bit delicate, but still easy enough. Works well in real world use.
I don't think that the AF sound is noisy or annoying.
My copy had a slight front-focus (less than 2mm, not objectionable in real-world use and easily compensated through the AF fine-adjustment of my EOS 50D)

Sharpness:
(Big GIF-image! 100% Crop)The Center-sharpness is very good wide open and excellent stopped down.

(100% Crop, bottom-left corner)Edge-sharpness is naturally worse, but still good.

(Light source at the bottom-left corner)Vignetting is noticeable wide open and well-controlled at F5.6, but

I neither had problems with vignetting, nor CA, nor barrel-distortion in real world use.

Canon or Tamron?:
I had a Canon F2.8, 17-55IS before and send it back to the merchant.
The Tamron does very well in comparision. The Canon AF was nearly inaudible, but in terms of speed, the Tamron nearly made an even match. In terms of accuracy, I even had less missed shots with the Tamron, espacially in difficult light situations and closer focus distances. I think it is also an even match in terms of sharpness. I experienced problems with CA with the Canon lens but I had none with Tamron.
The Tamron is smaller and comes with a lens hood. (Canon does not)  The price difference bought me an excellent tripod, a very cool camera-backpack and a B+W circular Polfilter, and I still had over 200 bucks left.
No regrets.