When I first started running I was a strong believer in quality over quantity. I used the FIRST plan, ran 3X/week, maxed out @ 30 miles and BQed on my first marathon. It worked for me.
In more recent years I started to increase the quantity. I did this over several years such that I maxed out @ 80 miles (for one week) during my last marathon. I also believed that going all out at the end of the run is the way to go. It worked for me.
Now with Tim I am training very differently. For example, this week I ran every day, 73 miles total, only in my aerobic HR zone (aside from a recovery run set to max at the lower end of my aerobic HR). In fact, most of my runs since the beginning of February were like this. No speed (aside from a TT), only few strides. And I got faster. My aerobic pace now, the pace that I seem to be able to hold forever averages at 7:45, consistently over the past few weeks. When I started to increase miles after my injury, at the beginning of February, my aerobic pace was close to 9. Of course, I am not saying that my improvement is due entirely to aerobic running; I am aware that my base has not gone away for the few weeks when I was injured. But, it is amazing to me that simply aerobic running is working so well in not only bringing me back, but also improving my aerobic pace in one month flat. I am really excited to see what I can do once we add speed.
Which brings me back to training methods...I continue to believe that most methods work, high mileage, high speed, HR training. But I am starting to believe that I can train smarter, less "all out", and maybe achieve more than I was before. Time will tell. Racing will tell. For now, I am really having A LOT of fun running and being coached. Best thing ever for me, I think.