Benefit of the Spider diff over a std diff?!?

[lincpimp]

So I was wondering what differrence a 8 gear diff (ofna spider) has over a std 6 gear diff in the way of performance? It has more contact teeth on the outputs, so is lighter fluid required to achieve the same limited slipo action? I can imagine that it is stronger, and possibly smoother.

I ask as I am planning to make a center diff for the new emaxx and erevo and might as well make a setup for a std diff and the spider. Some info from someone who has used both types would be handy, perferably in a racing enviorment. And if the design I have in my head works they will be for sale...at a good price.