Quaife vs WRD Diffs

I am looking at replacing the open diff I currently have with a LSD. The two units that will fit, from what I can tell are Quaife QDF7ZR, http://ift.tt/1SzKntn and the Williams Racing Developments WRD-CDD-3000, http://ift.tt/1SzKkhn. Anyone have experience with either of these that they can share? Looking at reliability, maintenance, performance, etc. Also if anyne knows of another unit that would fit I'm all ears.