I bought this lens when I switched from Canon to Nikon. I had been using the Canon 17-40, which I found pretty good. However, once I saw the images this lens was capable of (especially at 18mm) I was thoroughly impressed. It quickly solved my search for a wide lens for landscapes and general use.
Fairly lightweight; IQ punches above its price class; fast AF; common filter size; did I mention it was sharp
A little slow on the long end, makes you want to get a 35mm prime for low light, also because it's slightly less sharp wide open at 35; Could be more compact, perhaps, it is surprisingly long