When I bought the diff, I was told it was a 2-way. This means it has an equal amount of lock on acceleration and deceleration. 2-way diffs, or solidly locked spool-style diffs, are preferable for drifting. This explains some of the oddities and inconsistencies that the rear of the car had that I experienced while driving.
We decided to make the 1.5-way diff work. We shimmed it to increase the preload on the clutches to the point where the diff would almost be locked solidly. This would salvage things, as buying a new LSD was not really in my budget.