I’ve only used Humanoid but it seems to be pretty solid. There is some pretty minor loss of accuracy sometimes but the major issues typically stem from missing or additional bones - stuff like the Shoulder can mess things up - but its something you’ll have to look at on a per-model basis. You can easily remove any Optional Bones if they’re causing problems.
Using Humanoid Rig Type has a lot of advantages on the backend with scripting access and such.
I believe Generic is intended for abnormal rigs and stuff that may have more than 2 legs and/or 2 arms (spiders, dogs, birds, etc… stuff like that…)
Yeah. Humanoid bones can be easily adjusted through builtin tools.
Both Humanoid and Generic Rigs are Mecanim types.
Legacy rig is a older type that is used by Legacy Animation system that is different to Mecanim system.
My question is that simply converts a Legacy type to Generic/Humanoid type in inspector may cause any possible problem?