What alternative IRS diffs are out there? In particular, which are the lightest/most compact/tripodes/CVs/have limited slip etc?

I have heard that the Land Rover Freelander is used, nice and light and I suspect poss LSD. Also following a Honda version of the Freelander (cannot remember name) I could see nice compact diff and very slender drive shafts. BMW 3 series, LSD on most 6cyl, but suspect heavy.

The Freelander diff is only of use on the bike engined cars it can't take the torque from the other engines. Nice and light though.