I've used a Shorai LiFePO4 battery for a while (hundreds and hundreds of flight hours) now. I chose it over the PC680 because of it's light weight, and over the EarthX because of the high cost and questionable BMS claims.
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything