the real shoe guru wrote:
You're not a shoe guru. The "compression" theory is a total myth. This is why people can't even trust their local running stores.
Cook, S. D.; Kester, M. A.; Brunet, M. E., Shock absorption characteristics of running shoes. American Journal of Sports Medicine 1985, 13 (4), 248-253.
Right, looking for unbiased real world experiences. You have to see if the study was paid for by a shoe company or not. Whenever you get information from anyone, ask yourself if there are likely to be any motives, biases or conflicts of interest. Do they have anything to sell is a good test.
I think 300-500 is not too many miles if you are light and have decent form. Can go double. If you are overweight or have a pronation pattern that wears the same spot over and over you will probably get less.
Don't just replace for the sake of it.
Rotating two pairs is a good idea too for the reasons mentioned, especially if you run daily or even doubles at times.