The wavetrac works differently to the quaiffe as it transfers the power in a different way. It is a much superior product to a quaiffe.
This is copied from elsewhere but it explains it without me having to use my brain.
The wavetrac diffs have an entirely different operation to any other, and unlike other diffs they allow transfer of power even if the axle is not loaded... so if you lift a wheel in a corner, you still get power transfer to the wheel on the ground. This does not happen with other diffs. Explaining how they work is another post entirely, but you can read up on them here -
http://www.wavetrac.net/