Or just high speed dirt/gravel roads.
A few of the blokes on AULRO have them and reckon it makes a huge difference in driveability on gravel, just stops the hunting back and forwards of the open centre diff without the inherent understeer of a locked centre diff.
I'm hoping it also eliminates a bit of slop from the t/case, I have one, plus Maxi Drive low range gears going in this week, if I can actually get time in the workshop.
I was curious about these myself but have never cone across an installation manual. Is there much to putting one in besides refreshing the front and rear output seal/bearings and dropping this in - or is there some shimming and such required also?
I want one for running on snow-covered roads. My 80 series cruiser has a viscous center diff (similar setup) and it is an animal in the snow. I always found that the range rovers with the BW case performed better on snowpack than LT230 equipped discos, and I suspect it's the center diff.
The cruiser has a selectable center diff lock and engaging it (instead of leaving it limited slip) makes it handle way worse in the snow.
There is a thread on Pirate4x4 where Buck installed one in his race car (LS based V8 space frame lunar lander buggy racing thing). That guy could bend a crowbar in a sandbox and he hasn't broken it yet.