I'm looking to get some new shoes. I would like a pair of racing flats that I can train in and get, at a minimum, 600+ miles of use (I usually wear my shoes into the ground, so this may mean 400 for someone else). They should be totally neutral with no stupid support bars, extra cushioning, anti-pronation, or other gimmicks. They also need to be lightweight. Nothing over 7 oz is acceptable. I hate heavy shoes. Heel-toe drop should also not be more than 4mm and flat would be ideal, although I realize this is asking a lot with anything other than New Balance's Minimus line, which I have found to be grossly overpriced for what you get. Suggestions?