Anyone run one just in the front?
X2, I have the same set up and would agree with the type of wheeling we do a front locker is great. You might not like the noisiness and drivabillity of a automatic locker.I would go with a front locker first. The reason being is that it will allow you to pull your front end up, and onto an obstacle easier than your back end can push you up the same obstacle. It's like forcing your front wheels to climb with no ability to really grab and pull.
That being said, a rear locker is better than none.
I am putting a Detroit in my D30 this spring and leaving the rear 8.8 open until I can afford double ARBs.
I am sure others may disagree, but for the wheeling we do here (lots of boulders and logs and junk) the front locker first seems to be the way to go. If you wheel in an area where there is more smooth rock and sandy soil, mud etc, I may be way off base.