I revise vocab using the built-in SRS and revise old lessons now and then but not systematically. New, more interesting content is always better if available. Before I used LingQ, I had good success with Anki and earlier Supermemo for vocab reviews.
Although LingQ has no long-term diary or reminder system, you can click the share link at the bottom of a lesson and email the link to***** You will get an email in 2 weeks with a link to review the lesson. More info on this email reminder tool at http://followupthen.com