This is a great product for the price and traction you get. I got one for the D44a. The original price was 229 and I paid 299. It is now up to 400+ due to being discontinued and no other choices are available for the D44a.
I installed this in about 2-3 hours taking my time. It is great having the rear locked and I'm impressed with the amount of traction available in just 2WD now.
I'm thinking of going to put one in the front end (d30) because they are so cheap and easy to install.
I have over 10,000 miles on mine d44a aussie and no signs of problems. The clicking noises still occur but they've gotten less audible. Some people think that there's something wrong with the drive train but I could care less.