Shooting at f16 won't necessarily give you sharp images. In fact quite the reverse as you begin to get diffraction as you close lenses down. Diffraction will appear most noticeable in foliage which will look smudged to the eye. Try researching the optimum aperture for your lens. See here how to go about it:
http://www.usa.canon.com/dlc/control...articleID=1386
At 100% my 5d raw files look absolutely sharp.
Dell monitors are not the best for photo editing. They are not that easy to calibrate and will distort as you move your eyes from one side to the other. They are only fit for office and home computer use. You need one that is at least suitable for gaming. I got rid of my Dell monitor and replaced it with a HP w2207 (a couple of years old now) and that is remarkable for editing video or still images without breaking the bank.
You just need to consider what hardware you use for editing your pictures with if you want the best you can get from your camera files, and that might be costly.