There are some quotes on Bob Hodge's site that I think are very insightful. Here are some:
"When you begin to believe, that is when you will be on the right track to try and accomplish whatever you have set out to do."
Believing in your training is the most important thing, I believe. If you run miles, and lots of them, and you think it's the most effective way to train, than it will probably work, and work well, given you stay healthy. If you follow a Coe-esque plan, with proper aerobic conditioning, and you believe in what you are doing, it will probably work.
Snell, Shorter et al. ran WRs and won championships off of Lydiard and lots of mileage. Coe, Cruz, et al. ran world records and won champs off of speed based, lower mileage training. Each believed in their training, and worked their asses off, and this resulted in success.
No one in their right mind can say one way works and the other doesn't, because empirical evidence shows otherwise. One can argue that one way is more effective than the other, and bring up valid points. But we'll probably never know. Say someone runs WRs off of high mileage, who's to say high mileage is the key and not ridiculous talent. And the same goes for the intensity based, lower mileage programs.
I think one thing that cannot be stressed enough is sticking with a program over time. Years of development using one program, working hard, and a little bit of faith can go a long way. Switching between philosophies regularly breaks up one's consistency, harms one's confidence, and just doesn't work out very well. It can be worked through in the short term, yes, but it's immediately detrimental to one's running. Look at Alan Webb--two switches in two years and he is struggling.
This is not always the case, as lots of runners have switched programs and had great success, like David Krummernacker. But this brings me back to my original point that believing in yoru trianing is very important. Krummenacker believed he made the right choice and had faith in his coach, De Oliviera, and he suceeded. A guy like Webb doubted his coach, left him, and obviously doubts what he's doing now, and it's led to disaster.
I would say that no one way is right. But as long as you stay healthy, trian consistently, train a lot, stay injury free, and believing in what you are doing, you are on your way to success. There's always going to be failure, injury, and things that make you doubt the efficacy if what you are doing. It happens. But if you keep at it, train smart, as a whole, this will lead to success.
This is my .02