I've got a couple of the BT injectors and I've had no problems with them. Personally, I like the lock in nozzle just because I feel it's safer. Initially, I popped the nozzle out of the CCM injectors several times while evacuating the injector. It was my fault and it came from inexperience and it hasn't happened again in months. Murphy's Law still reigns supreme, however, and it will only take one accident for bad things to happen.
With all that said, I love the CCM injectors. They are light, precise, and easy to use.