Thanks a bunch this sheet is just what I needed!
Although the 08 legacy is incomplete on the rear diff I think it's supposed to be open not blank. Also the line US Impreza RS MY99-01 / Legacy GT MY99 says open/viscous pretty sure viscous means limited slip right?
And I posted in another thread about the 01RS: it might have been the limited slip rear diff, a problem with the center diff not transferring power front to rear, or just bad tire choice on my part that it did poorly in the snow conditions here where I live.
Unfortunately I no longer own the car so I've no way to be sure, but for now I'm going to stay away from limited slip rear diffs on manual trans for the snow driving I have to do just in case since every Subaru that my family/neighbors own has an open rear diff according to this chart and does fine.