[Zope] User Source choices

[seb bacon]

This is a bit off-topic, but I wondered if anyone has any opinions on
the matter.

I'm going to use LoginManager for my user folder stuff, and I'm
wondering which type of DB to use to store user information.

Has anyone any advice about this?  Here's some of the free choices with
what I know about them:

MySQL is my first choice because I know it well
postgres has transactions, stored procedures, but can scale badly
SyBase I know nothing about
LDAP (e.g. OpenLDAP) is optimised for this kind of thing, but I'm not sure I've quite
grokked it yet

Should my choice be dependent on the quality of the adapters available,
or are all the adapters much the same?

any comments appreciated,

seb