[Dovecot] SASL authentication

[Tom Allison]

I was browsing the wiki and found a section on what appears to be as 
close to "exactly what I'm looking for" as I've seen in a long time.

http://wiki.dovecot.org/moin.cgi/DovecotPostgresql

However, I'm not inclined to do very much "blind" configuration on my 
machines without first understanding the what/why of it all.  My theory 
is that this helps me with the RTFM syndromes later.  Hopefully.

My current dovecot installation is based on pgsql authentication with a 
single domain and files being placed in a $HOME.  It's as if it were 
/etc/passwd based, but the passwords are different.

I would very much like to migrate this into a system which supports 
multiple domains and this Wiki seems to be the best means for that.

However, I didn't use SASL authentication.  I was emotionally scarred 
trying to use SASL with a venture with Cyrus-IMAP under different 
circumstances.

Could someone explain why SASL is a good thing in this case?
Does it allow for something more, lead into future developements?
Most of the rest of this general paper I do understand, but the SASL is 
the only part where I'm not sure if I must do that, want to do that, or 
can live without it.