The slim wing has the advantage of being faster because there is less drag, especially with the removal of under camber and a finished trailing edge. The down side is less lift and higher stall speed. Also, the less drag aspect helps to allow the plane to 'carry its weight' better as you don't have the floaty feeling associate with the normal FT style wing so it really feels like a different animal to fly.
If you want a slower, more stable at slow speed plane, the normal FT style wing is a better bet. If you want to go fast the slim wing is night and day better.