I've had both AT-X and the AT-X pro lenses and the 2.8 series lenses are spectacular. They are really nice and solid, and the image quality is fantastic. The older plastic-framed lens, I had the 19-35mm, was good, but not as solid a lens as the brass and glass 35-70 f/2.8 that I have now. If you have the option, go with the pro series, but you won't be disappointed either way.