Steve, I’m not totally sure of the importance of the runs. In 2002, I actually did very few, if any, midweek runs of more than 12 miles (about 80-85 minutes, give or take) but I was doing a lot of 12 milers. One thing I would question is if it’s possible you’re hitting the workouts a little too hard, which might be making the midweek long runs seem harder than they should. Just a thought to ponder.
Zeke, do you know where you read that about the runs? I remember something similar about fat utilization but I don’t remember it going anywhere beyond that. Aerobic development seemed to be consistent. I’d be interesting in reading this if you knew where you got it from.