I have gone away from the CC BEC I have heard too many stories of them failing and than instead of not allowing current to flow they do and will fry at least your Rx, I have since bought a Western Robotics HV BEC wich is rated up to 60v, they can be set at 6v and if you run a steering servo that has at least 250 in/ozs you wont notice a difference between 6vs and 5vs.

As fas as LVC is concerned I set mine at 3.3vpc, I have found that the vehicle has just started to slow down at his point and it gives you a little extra insaurance against allowing the votage to go down too low