It probably means that it has 3X better value. If I spent $1 previously to do X, I can now do 3X for the same $1. I think this is more intuitive for most peopl

It probably means that it has 3X better value. If I spent $1 previously to do X, I can now do 3X for the same $1. I think this is more intuitive for most people than using percent difference for the same reason using a raw ratio (speed up) is better for expressing performance improvement.