The whole 'sport vs street' argument is a bit of a waste of time from my perspective, as the best approach for me is based on sport training, adapted for specific real-world jobs and needs.
Ringsport is the breed test that brought the malinois/mechelaar to prominence, developed the animals themselves and their training and handling, and gives us a benchmark to measure working abilities.
These programs, or our approach to them, shouldn't lose sight of the fact we're produing service dogs for the real world, and so communication with and feedback from law enforcement, the military and high-level security professionals should inspire and influence how we engage with 'sport'.
We look for certain all-round qualities in the dogs, and adaptable methods of modifying the dogs' behaviour to specific goals and working with them as a team.