This plugin works well for me. We're using it against Active Directory on more than one multisite installation. The advantage to this plugin to some others is that it's designed to be a multisite plugin and just works in that configuration. Many of the other plugins out there that work with LDAP and/or ActiveDirectory specifically were first single-site plugins that became Multisite plugins and as such are clunky.
The settings make sense, and it didn't take me much troubleshooting to get the plugin working.
If you do run into trouble, make sure to set LDAP_DEBUG_MODE to true in ldap_auth.php to give you some errors to go by.
I agree with @boxcarpress's review that it's bad to not store the Search User Password value in the database in plaintext. This can be mitigated a little bit by making sure that the rights for that user are buttoned down to just performing searches. This would be a good area of improvement.