i juz tested the demo NF800 4UG5 at the thai open considering the 4U version pack a heavier head compared to the NF400 4U, shaft is slightly stiffer but not as stiff as the DZS, drive is as fast as the NF700 so is the lopping while the smashes are more powerful most prob due to heavier head wt, wondering if i should get the 3U or 4U 
