I consider Knut a friend, so I would like to lend support for his coaching. It is my analysis that three main elements of Knut's approach are vital to any coach's success in working with distance runners. First, he emphasizes aerobic conditioning as the primary method of improving performance in the long term. Second, he doesn't rush the process. Third, he establishes good communication with his athlete's and seeks to understand who they are and where they are in life and running.
The use of abbreviated rests between rests has hurt more people than it has helped. If one has a very strong aerobic foundation, then short rests won't tear a runner down much in the short-term. In the longer term, an athlete may run the reps faster but their race times will either stay the same or get worse. As a general rule, the benefit of the short but fast reps is not in stamina develoment but, rather, in force production and concurrent efficiency. A runner increase power by recruiting more motor units and in patterns that are effective. Additionally, the expenditure of energy is reduced as coordination improves. The difference between your average marathoner doing 200m reps in 30 seconds and your average mid-distance runner can be as much as 10%. Why? The marathoner has not developed the capacity to generate force needed for such a speed without using a lot of energy. In the converse, a mid-distance runner running at 80% of VO2 max (marathon race pace) is likely to use far more energy than a marathoner doing the same pace.
As you can see, then, a portion of effective training centers around creating force and saving energy. Race pace training does enhance this quality (at or around race pace). The key to use race pace training with caution, with sensibility, and with forethought. It can tear a runner down just as quickly or more quickly as it builds them up. This is key. Knut has done a good job, I believe, with Susanne in this regard. He hasn't abused her with short recoveries between fast reps or had her too these types of sessions too often. All the while, he has kept her aerobic conditioning at a premium.