Ronald: I rented this lens expecting stellar performance....it certainly delivered! It took me less than a couple minutes of playing with it to realize that it was not a toy but a precision tool. You realize that you have an precision instrument in your hand. I used to own the Nikkor 14-24 f2.8 but sold it when I realized I seldom used it wider than 16-18mm or so. I compared this lens' files to those of the 14-24 and found a marginal increase in sharpness in the center but a distinctly noticeable increase in sharpness in the corners. It took me a while to respect the fact that you can basically leave this lens at infinity and not bother too much with the focus! The focus ring is silky smooth should you decide you want to use it however. There was virtually no barrel or pincushion distortion as all straight lines stayed straight. I would certainly recommend renting this lens for any special project or trip where super wide would come in handy. It has made me rethink my scarce use of a super wide lens in the future.