The polstar volvo c30 used haldex awd and quaife diffs and as seen on top gear had no problems launching in the wet, and seeing as a haldex unit is also used on the veyron then yes not of much use for performance cars .

If you talking about a first gen reactive haldex unit then I would agree your better of with something else, as these require some slip to build up pressure, so not much use of the line which in a fwd is when you need it most, there will be pressure when on the move.

3rd and 4th gen units are instant, pretty sure the kuga uses a 3rd gen of course it will all depends on how the haldex controller is programmed so just using it as is from the kuga may not give the best performance results.