Are the rubbers really that different from each other?
Do you really notice that much difference between rubber compounds? I've only ever used Vibram, and I don't notice much difference between Edge and Grip.
For example, I resoled a Solution with Edge, and their performance is almost the same. I weight aprox 62kg.
But sometimes I read comments that it's like night and day between Vibram compounds, or compared to other brands.
What do you think?