In my experience I have played a lot of my rackets (Prestige's and Radical Tours) with both black and clear grommets and the the clear grommets definitely feel softer and in my opinion much better than the black ones.
I have recently installed my i.Prestige MP frames with the clear grommets and the difference is very noticeable. It is hands my favorite frame with the clear grommets.
I have four IG Prestige MP frames. I really enjoyed the frame with the clear grommets not so much with the black caps.