[codeduck]

No. There are various types of LiFePO4 - some are as you say used for receivers etc but the ones I am specifically referencing (and perhaps should have been more explicit about) are the A123 systems Lithium Iron Nanophosphate batteries, which are capable of 60C burst discharges and 5C charging rates. These are definitely used as primary power-packs for flight - I flew with people who were using them when they first came out.

[ricket]

Sorry. I googled to check before posting too, but didn't consider specifically the A123. It still looks like it is an uncommon choice for main battery pack but I can see how it's at least feasible (I probably wouldn't go for the tradeoff personally).