Having first used Hi-Tech Silver Shadow and Silver Shadow X4's from around 1991 I have continued to use them ever since. I have tried others that left me with shin splints and other niggling difficulties and always returned to the old faithfuls. I love Asics for the gym but for road running, and I have completed literally thousands of miles over the years, Hi-Tech Silver Shadow have always provided me with both the comfort and reliability at minimum cost that most plodders need. Inexpensive and easily located through the web. Like others, I dread the day that Hi-Tech stop making them.