oh, I though cusco and quaife were both helical, I guess only quaife is. So i guess I should have said OEM is helical like quaife--Torque biasing. Clutch diffs are true LSDs.

How well a clutch type alows you to turn is largely dependent on how its adjusted (how many plates are engaging), the reason people often have understeer issues with a clutch type is because they have it set on too hard a setting. Only way to fix that is to remove the differential and re-arrange the clutch plates, which is more work than most people are willing to do. I agree that clutch types can be good for any type of driving, but many people are too lazy/confused to adjust them to the appropriate setting for theyre driving style.