I currently have a Black Diamond and a Balance, sold my Pro QD a few months back. All are good BC's but it seriously depends on what you demand of it, wether it be hunting, teaching, pseudo-tech, or just to be out in the water. As a note, I am more inclined towards back inflate systems than jacket style.
Black Diamond: I use it the most for recreational, because I am usually with students or doing wreck/deep or dives where I am hauling alot of gear/equipment or extra cylinders. The lift and attachment points on that BC is more than enough to handle the serious levels recreational diving. I don't quite use it for tech as I have dedicated gear for that. It is by far the most comfortable BC I've ever worn. Only drawback I feel is that it is a VERY VERY bulky BC, not easily packed if space is a must.
Balance: I find that the balance is a good travel/streamlined BC, where you don't need to carry any additional gear. If I am doing fun dives where I don't have any worries in the world, I tend to stick to this one. I use this BC particularly in the pool because its light weight, small, and I dont need all the attachment points/lifts while teaching in confined water. Plus its cheaper to thrash a Balance than it is a BD
No input on the other mentioned BC's.. sorry.