Just some background info, I'm a high school xc and long distance track runner. I average about 40 mpw. I am specifically looking for a shoe that is very responsive, shock absorbant, comfy, well cushioned, and nuetral. I had been previously been running in the Saucony Kinvara 6's, but after going through 3 models decided a change was needed. I'm looking for something a bit heavier, roughly around 10 ounces. One shoe I have looked at is the Asics GEL-Nimbus 18. I just want to make sure it is responsive and will last at least 400-500 miles. Any responses or suggestions are appreciated!