I have been sober for nearly 20 years now and drug free for maybe 10. I stopped drinking when i realised i was developing a problem and after several failed attempts at controlling my consumption. I carried on taking drugs (marijuana, MDMA and tobacco) mainly at weekends, parties and festivals for several years. So I have been pretty free from intoxicants for at least 10 years now -though I have taken cold remedies when ill and been quite disturbed at the intoxicating effects -I am currently trying to stop using coffee as i have begun to realise the strong effects it has. All my life I have been a coffee drinker.
After all this time its quite hard to put into words how I have come to see drugs/alcohol. To me there is no difference between legal and illegal drugs -and in my opinion alcohol is a drug like any other, it just happens to be legal in most places. I think many people would benefit from total abstinance for, say, 6 months or so just to experience the many insights that would provide. e.g. the way that people respond to you both good and bad when they know you dont drink or take drugs. It would also show how important the consumption of drugs/alcohol is in most societies/cultures
As a precept its the one that i find easiest to keep. Though I agree that for the laity the precepts are not hard and fast rules I do think that it would be hard to be taken seriously as a Buddhist with a beer or a spliff in one hand
While not my initial motivation I beleive that there is no place for intoxication on the path and with that in mind think that even one drink or small amount of any other substance could serve no useful purpose