Tremendous lens for a crop camera, very good contrast, quite sharp wide open and very sharp when closed. It is a bit heavy but the build quality is decent. The focusing mechanism is fast and relatively quiet, but on the other hand, the stabilization mechanism may be audible when shooting videos. The mount is metallic and the aperture does not change during zooming. In short, it is a very good choice and personally, I do not regret buying it. The only downside is that it has been mentioned that there is a possibility of dust getting behind the front element, but it is easy to clean for someone who knows how

I am a professional. I bought it in October 2014. I have used it in mysteries, inside churches, but also in theaters and dance performances. My camera is the Canon 70d. I am extremely satisfied with the lens. Its photos are amazing and cannot be compared to any other in a crop (dx) body. It is the top choice for professionals with a crop body, but also for amateurs, as it is affordable. I highly recommend it without hesitation!

This lens is below average... below f/4 the distortion starts... at f/2.8 it is very pronounced... unfortunately, it is not worth the money... the 24-105/4 L, which is almost the same price, is better with closed eyes...

I had this specific lens in my possession for about a year, on a Canon 400d, and it left me with a very good impression.
Due to its low focal distance, you can cover a wider range of information without having to move away from your subject. It was very fast in focusing and its performance at f2.8 was exemplary. I mainly used it for portraits and landscapes. Someone might find it heavy, but I consider it a matter of habit. It suited me better because it made my hand steadier.
I would definitely recommend it to anyone who has the financial ability, otherwise there is the alternative of the Sigma 17-50mm F2.8 EX DC OS HSM or the corresponding Tamron, with the former being slightly better.