I've been using the 18-135mm & 28mm f/1.8 prime for landscapes and general use lately and ultimately found that neither really filled the general use niche as well as I had hoped. I just picked up a 17-40L to fill the void.

The 28 is fantastic for what it does well. It is a good, reasonable cost, wide aperture prime that can deliver the goods especially at f/2.2 or narrower. It's great for low light. It's not great for landscapes. Corners can leave something to be desired with fine detail like trees and 28mm on a crop really isn't that wide.

The 18-135 is a lens of convenience, but not critical review of image quality.

I tried the 17-40L out and was taken back by how great of a job it does. The image quality is very good with sharp details and great colors and contrast. Lots of people suggest the 17-55, but ultimately it wasn't for me. Build quality and FF compatibility are very important to me and lower cost is nice too. I look forward to taking some excellent fall colors pictures over the next couple of weeks and on an upcoming trip to the Caribbean.

Dave