I find that amitland is useful as an assessment skill, that's about it. Mulligan takes Maitlands concepts a bit further by making on do PA's, AP's alonf the line of facet/joint alignment (something mr Maitland forgot, and Mulligans MWM's aren't a breakthrough either only a name to something everybody has been doing in the belief that it feels the riught thing to do. Well it does for me and i use it often to help "budge things". Carr & Shepherd are great if you need quick results in a healthcare system that is time poor and cash empty (name one that sin't) The results aren't pretty though and bobath is a better assessment technique. Bobath can also produce lovely stroke rehab results but you need 2-3 years 3-4 sessions a week!
As for nordic, it's nice and it is a bit older than the rest. MET is really taken from nordic and can be a nice realignment tool for the pelvis, SIJ etc. Don't think much of the assessment but do like the techniques, "shotgun" especially. but like most osteopathy I believe MET is a useful reactive treatment tool, yet not a proactive approach to general well being. I think one of the best courses I have ever done is Karen Ginns (Sydney Uni - anatomist) shoulder course. A nice refreshing view from someone that is primarily an acaedemic.