SSO questions

[signal15]

I'm looking at using the SSO plugins for Google, Facebook, and Github. I have a few questions before I install these:

1. Are they all stable?
2. On the registration page, are all options for registering presented, including just registering with an email address?
3. What happens to accounts that were registered through SSO if I eventually delete the SSO plugin that the account was registered under?

[PitaJ]

1. I think we use all of them here, and I haven't heard of any issues.
2. It's configurable. By default, normal email-based registration is enabled. You can disable it in the ACP.
3. Their existing browser sessions will persist, but they won't be able to log in without the SSO plugin.

[signal15]

If needed, is there a way to convert SSO accounts to local ones? Obviously they would require a password reset.