LDA versus LMTP

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.