BCDs (along with your regulator and cylinder) form the third part of your life support equipment. Not only does it help you ascend at the correct speed, but in a pinch you can use it as a source of air. However BCD servicing is often put off by divers.
When we service your BCD we take the utmost care to ensure that all parts are clean and all sealing surfaces are well... sealing! That way you can be sure that you won't be "that" diver (dragging half the seabed along with you due to a faulty inflator).
The buoyancy control is up to you though...