I agree with Steve W's sentiments.This has obviously been discussed at length before,here and elsewhere.However I have found some of the DIR brigade to be very approachable,balanced people who have an interest in their diving and some great level of experience.They make their decision to adopt DIR (or not and take some of it's philosophy/practice which they like)to build upon their knowledge etc.There are of course exceptions to this,but there's tossers in all walks of life is'nt there.As in other fields if someone is taught specifically to do something one particular way and led to beleive it's the best then it is very hard to change their opinion.(This can create probs if it goes pear shaped,more from a phschological point of view as they can't beleive it's happening to them).Anyone who's ever met a newly trained US Marine or indeed read Blackhawk Down will know what I'm on about(I use these 2 as an example only,it's not just the Yanks who suffer from this,we all can!)I found this link some time ago which gives a breif overview of DIR and is worth a read.Take care,Hobby.
http://www.diver.net/seahunt/fend/f_mhk1.htm