thanks for fast response. Yup, I know what X means however from where I live there is not much choice of NS boards and there is no heritage X left only regular one. I' ve had SL few years ago and it was fun but for now I'm looking for something different. I was also wondering if I need wide board. From your reply I assume I do so there is unfortunately (or not) only proto in X version. So an availability of the board made choice for me. Thanks for help!