Are there any significant drawbacks to joining a SQL Server machine to the domain (i.e. security, performance, etc)? Our box is currently off the domain so we just manage users locally, but we were thinking that security may be a little stronger with it off the domain.
Edit - Forgot to mention, this is a database server for a public-facing web app ... not sure if this changes the answer (the web app is in its own DMZ).
Add it to the domain. Performance issues due to adding a domain would be so minute if anything at all.