LDA versus LMTP

[Steve Matzura]

My system has a great big four users. The Dovecot wiki says LMTP is
more efficient, and someone on IRC told me I'd need it if I were ever
to use sieve, which at this time I have no intention of doing. Should
I stick with LDA, or just implement LMTP so I'm ready if ever I need
it in the future? The bottom line is, it's unclear from the wiki how
to explicitly specify use of one or the other, so that's my question.