So a couple years on and I will say that this diff was a great value buy. No issues so far (knock on wood) through many track days and hard laps. I have since moved up to stickier rubber, and the diff hooks up no problems.
I have noticed a little slip when the axle hops a bit over bumpier sections of track, but the reaction of the diff is very quick and doesn't really impact lap times at all.
Like all the other guys on here have said, a diff transforms the car and is the best mod you can do to the clio, hands down.