I was reading here and there on several forums about this lens. I was extremely skeptical at first as I always equated Tamron with the stinkiest of the big 3 third party lenses (Sigma & Tokina being the other two). However I saw a review site with the MTF curves and they were astounding. Then I saw a guy's in-depth comparison between this Tamron and the stalwart Nikkor 17-55mm. To my surprise they were both equal!
The Nikon 17-55mm was of course almost triple the price of this Tamron. Sure it may be better built, but I could buy three Tamrons for that price. Also I don't know how you shoot, but I could do without having Nikon's 10 pound lens on the front of my camera -- especially at this walk-around focal length!
My first wedding with this lens had me shocked. Shocked that I had to hit a whole lot of photos with a layer of blurring because they were too sharp. Seriously, out-of-camera photos looked like I had already applied an unsharp mask to them.
Corner sharpness is not 100% perfect, but neither is the Nikon's 17-55mm. It would be unusual for this focal length to have edge to edge sharpness anyway.
Bokeh is great. No complaints there.
As I wrote on top, I have no idea why Tamron makes the whole body of the lens a zoom ring. It really makes swapping out lenses harder than it needs to be. I'm sure once I get used to using the zoom lock it won't be a problem, but for now it's a bit annoying.
Anyway, highly recommended.