SGX: too small if you are tall?

Hi, I bought the SGX several years ago. I looked at the models page recently and for the SGX it states it is best for those 5'6" and under. I am 6'3". Okay so I have not used it often so no super orgasm. I did try it the other day and followed the instructions. I did not feel it hit my prostate.

From those with experience would you say I should try to work at it and use the SGX or is it too small/short for a guy my height. ie. will it not hit my prostate because of my height? Or is it just a matter of using it more often and I will get the benefit? Or should I just jump to a bigger one and not waste time trying the smaller SGX?

Thanks.