My $.02 worth .... judging from their ratings I would think that Hobby King LiFe batteries are rarely used for electric flight. They're a good battery as a flight pack for the radio only but I'm not so sure about radio and motor combined.

The only LiFe ratings I'd really trust are those on the cylinder cell, A123 batteries as they have been around awhile and their ratings are proven accurate. Those batteries are bulletproof. As you know their downside is their weight, capacity and voltage .... not reliability. For most people, LiPo power has just proven to be better for motor power.

I'd just go with LiPo batteries as intended by the mfgr. LiPo ratings are fairly accurate and you know the whole system will work with them without modifications as provided by the mfgr. With a good charger and decent LiPo batteries, they are quite safe as proven by so many users. If there were major problems, the forums would be full of the reports but in fact, such reports are extremely rare.