This picture was done to compare a similar picture taken with the 17-40mm lens at:
http://www.pbase.com/image/58871224

I see three problems
1. The fisheye effect. This could be fixed if I had the software.
2. The lack of saturation and most notably the reflection off the water. I don't have a polarizer that will fit on this fisheye lens.
3. Slight loss of sharpness.