I don't have a really deep grasp of either one to be honest but I guess the main point is that Cashu mints are run by a single custodian whereas Fedimints are meant to be operated by multiple custodians so that no single one of them can rug.

I found the Cashu tech stack to be a bit simpler and easier to get up and running in a self-hosted environment and since I don't have anyone in mind to be a joint custodian with me at the moment anyways I figured I'd go with that for now.