I have always used a Sampras/Federer classic style motion, but my rotator cuff has been causing me problems lately. I know Roddick didnt develop his motion for this reason, but when I copy his motion, it seems much easier on the shoulder. I don't use a Pure Drive, so I don't get huge bombs with it, but it is still pretty effective. Anybody else switch to the Roddick style? I think it looks less asthetically pleasing to the eye, but my shoulder tells me to just forget about that!