GS75 is more comparable to NS850 as they are of the same weight. To my opinion NS750 is to light, a slow swinger will benefit from heavier shaft, or you better off using graphite shaft weighing 60-70 gr.
Tried both. Prefer NS850GH over TTGS75 for both feel and accuracy, not sure but perhaps GS75 is more flex.
NSPro recently released V90 and now am using this, even better than NS850.