There is a new article about MLSN by Trygve Aamlid and Karin Juul Hesselsøe, available in three languages (including English) on the STERF website.
I think this article is excellent. It gets at what is different about MLSN, points out a few strengths and weaknesses, and discusses SLAN and precision fertilization (also called demand-driven fertilizer) too.