Fedi has a better association between minted ecash to BTC reserves than CashU through cryptography, however its advantage is also a disadvantage. Fedi requires coordination of multiple people to keep its onchain payouts functional, and there is not an explicit subsystem to incentivise participation of the guardians. It's lightning-reserves are generally not 100% of its total minted ecash (by design), and up until recently, it could be at most 50% due to its non-native support of lightning.
Cashu only requires one "Uncle Jim" to run a mint, and it's power is in diversification and reputation. A structured incentive exists to keep a good mint running because the single owner recieves all of the TX fee profits. Unlike Fedi, cashu natively retains 100% of its liquidity on the lightning network. The ability of wallets to allow multiple mints custody cash-on-hand creates a competitive market that naturally lowers fees and incentivises the owner to guard their reputation.
