After watching a long video about all the settings on a 1D III, I tried this one on my 40D.
1. Shoot in RAW, because the sharpness values set on the camera has no effect on the RAW result.
2. Select a profile, I used Neutral, and set the sharpness to its maximum. In my case - 7
3. Take shot and zoom in when you chimp. Notice the sharp look and feel in the LCD.
4. To verify, set the value to zero and repeat the shot
5. Chimp again and notice the soft look an feel when zoomed in.
I was amazed to see my 40D showing sharp results on the LCD. My neutral is now set to 7 and will stay there for the benefit of chimping.
Feel free to add more advice.