The worst case of turbulence?

[bingofuel]

I agree wake turbulence is not well understood and rarely taught unless training from large airports.
The trouble with the guidelines of 4 miles or 6 miles behind the aircraft generating the wake vortices, is that the vortices dissapate with time not distance. In typical light aircraft 90-100kt speeds, 4 miles still gives you well over 2 minutes, and it is very unlikely you will close on the a/c ahead, so the time increases. But should you be following in a a higher performance a/c flying a faster approach , say 160kts to 4 miles, your chances of an upset are much greater, as 4 miles spacing is only about 90 seconds behind the generating aircraft.