I haven't had any problems with OpenLDAP in the past.  We're not using
it right now, but I'll likely be doing something with it in the near
future.  To effectively manage the OpenLDAP server for simple user
logins and system accounts, look at the commandline tool called "cpu".
Yes, bad name.  Simple and effective.  There are some nice GUI and WebUI
tools out there as well.

Remember, with LDAP, you can stuff a lot of information into it, and
most of your essential network services applications have a back-end to
query LDAP directly or can go to PAM for the information.  i.e. SSH
keys, Kerberos keys, passwords, server configurations, home directory
locations (for autofs), etc.

Don't be scared away from OpenLDAP.  It's powerful, flexible, and
reliable... in my experience.

Chad