I'm just generally impressed by their community efforts vs cFS. They really do their development on GitHub - not just a place to push out source, but issues, PR

I'm just generally impressed by their community efforts vs cFS. They really do their development on GitHub - not just a place to push out source, but issues, PR's, discussions. FPrime has some rough edges, and it takes a bit to get used to, but the team's interest in continually improving the core for a wide range of users is the differentiator.