hmmmm. When I first got my Tisp, I couldn't hit $#%#%&# with it. Then, I realized that there were many factors contributing to this: tension, stiffness, longness, my own noobie skillz etc. I also felt alot of vibrations, so I did an experiment. I added about 2 more layers of Supergrap over the g4.5 grip. After playign around with it, it was much better. The overgrip dampened the vibrations a little, AND it also made me grip my racket harder. Before, I was used to gripping it too loosely even when I made contact with the shuttle because of the small grip. Now, with a larger grip, all I have to do is grip it a little tighter and I am able to hit the birdie quite well now. So yes, grip size does matter, IMO.
