On discord someone brought up Navcoin being better for anonymity than Sigt, does anyone know if that's true?
NAV looks like Zcash and its Z adresses (however I didn't look in details)... On the paper it seems anonymous, but now we know zcash probably has a backdoor, I would stay away from these coins.
SIGT is clear about privacy : it is given mostly by the TOR integration and the fact that logs are disabled on the network.