Leather grips do make a difference to the feel as well in my view, not just the weight and balance impact. Most of my rackets come with one already, but every now and then they have a synthetic grip that I usually replace. The leather not only adds bevel feel, but the vibration absorption is somehow different. I find the response off the string-bed feels more solid, even as if the tension is slightly higher, because the leather seems to dampen vibrations in a different way to the PU most synthetic grips are made from.