Im sorry to say it but, a change from the standard live axel to this type of rear end would just add weight and complexity for little reward.

Camber and toe adjustments can be made on a standard diff housing. And if more than 1deg of neg camber is required, a fully floating axel can be employed with only a little increase in weight.

The extra weight of things like the CV`s, floor reinforcing and brackets to hold the diff in place aswell as the De Dion tube would nulify any percieved benifits.

I doubt there would be much improvement in unsprung weight,
and im very confident that total weight would be a lot higher than the standard diff. Even using an alloy housing. This extra weight would surely be a backwards step in total performace, even if there is a slight improvement in unsprung weight.

The only advantage i can see, is the prevention of spring wind up under heavy acceleration.