RE: MPI Regulators
The only "single" thing that could fail is the regulator in the SuperReg... if one batt fails, it's isolated from the other.
As I mentioned earlier Regs do not play well together, so it's not a good idea to use two regulated packs into one receiver. Something about one ends up drawing the most power and you find one pack is drawn down real low and the other hardly at all. That is what I was told from Rich at Smart-Fly.