I switched to EarthX 3 years ago and so far so good. I love the weight loss and starting power.
The more I learn about the LiFePo4 cells the more I like them and trust them. EarthX uses prismatic LiFePo4 cells which will typically be 4 larger cells wired in series to get the 13.2 volts. Could be more cells if they are a custom voltage. I am sure someone here knows all the facts. Here is a teardown of EarthX. Not sure if this is a current model. EarthX Teardown of failed battery.
I wish the cells were better supported than just some foam.
I have really enjoyed watching videos like the one below from Will Prouse to learn about how these batteries are built. In general, they are very simple to build yourself and I plan on replacing my boat batteries this year with some homebuilt batteries. You can build a very nice 100ah battery for around $500 with a nice BMS (battery management system). They are either assembled with smaller individual cells like the Battleborn in the video below or prismatic cells (second video). Prismatic cells are much easier to use as a hobbyist since you don't need to spot weld them.
Example of prismatic cells.
Honestly, I would have not issues building my own batteries for my plane. I think I could do a better job, use a better BMS with GradeA prismatic cells.