Thx guys!
Well, I think that on a track with low or medium traction a good ball-diff will outperform a gear-diff.
But if you're lazy (like me) a gear-diff may be better than a messed up ball diff
Jokes aside, on astro (high grip) though I think the gear-diffs may have a future in 2WD, but need to test first...
How about the X-6 or S2, can I make the AE gear diff fit in there???