The reason I use it is because it gives you more feel . It says not to use a big operating cyl, I think they mean a much bigger cyl, the nismo cyl is only a little bigger than stock, ""Do not use with a big operating cylinder, which may result in a misshift due to insufficient stroke volume.""
Before I installed mine I asked a race team in Japan , they told me to use the Nismo cyl and I don't have any issues at all besides the normal rattle that all 6 speed getrags have. I also asked If we should use the carbon clutch, they told me not to use that for my application.
If you are happy with the normal cyl thats fine but I can assure you you will not run out of travel using the Nismo.