the drexler and especially the os giken are track-oriented setups in my opinion.
for drifting-only i would have chosen different setups with more lockup and more preload.
i don't judge the units only for their drifting capabilities... i test them at a driving center with various options of u-split (one side slippy, one grippy) tests.
and if course i judge them on how they feel in everyday (hard) driving.
so i think i can finally judge quite well how a certain lsd setup behaves in what situations.
and a dedicated track setup would not necesserily be the same for everybody. a slick-tired, competition coilover, pro-driver driven car would be set up different than a weekend-warrior with street tires and an amateur driver.
if someone wants an lsd having set up from me, i ask a lot of things on the setup and dedication of the car and what behaviour the driver wants. then i would suggest a certain setup, build it and have it tested. in general this fits quite well then ;-)
if someone is not completely happy, i would reconfigure and finetune the setup along the behaviour that was out of what it was expected to be. (but this needs a really skilled and experienced driver really)
the reason for my detailed testing is that i had the impression that no one else really has done it so far (works team in professional motorsport have done and still do for sure but won't share their findings of course).
and when i see what crappy standard setups are being delivered to customers there is definitely a need to test what really works and what doesn't improve performance and traction as much as it could. (it is like fitting a 3-way highend coilover kit with an wired standard setup... you'll need to do a lot of testing to find the best setup for your requirements)
and often, the philosophy of the various lsd builders is completely different. just look at the push/pull locking ratio. cusco sells 1-way diffs for the m3 as standard (no lockup on decel at all), the other japanese companies sell at least 1.5 way setups (some lockup on decel, but less then on accel), zf sets their bmw units to 2way (accel and decel have the same lockup) and drexler even does more lockup on decel than on accel. this is wired indeed. but you can change this easily!
what really makes sense for which driving situation i will try to find out myself.
it became a hobby to me... ;-)
i already tried some dozen different setups in my other bmw race and driftcars.