I have a Nikon 7000, cropped sensor, primary lens 18-200 (27-304). I am looking into buying WAL, mostly for landscape/others, does not have to be nikon, but have looked at 10-24 & 12-24 (which are 15-36 & 18-36mm on cropped sensor). I like the 5 year warranty with Nikon. The more I read, the more confused I become with pros and cons. If anyone has any suggestions that would be very much appreciated!!!! THANKS