Depends on who you trust more, a single guy mint or a federated mint if you know how many and/or who they are. Just bc something says it's a federation, like fedimint, you don't know if it's actually secured by many members or just one person. So I would say in both cases it dependends on who do you have more trust and if the mint is able to be maintained long term and has good communication channels if something goes wrong.

Why are so sure that the 5/7/9 (whatever the number of) privkeys composing the Federation are not effectively hold by the same entity?