I know, I have even looked at some 40C discharge / 12C charge LFP recently as I plan to build an electric go kart at some point in the future. But it costs $2 / Wh (retail) and its cycle life is about 1000. Compare that to $0.5 / Wh or so and more than 2500 cycle life for PbC. There may also be other differences in robustness, but I do not know specific details. The price of PbC may decrease even further as Axion does not use any expensive material and early this spring they have managed to automate the last bottleneck in manufacturing (the carbon sheeting process). Once they have the electrodes (their assembly was already automated two years ago), they are plug-in elements in standard AGM batteries.