I am using 3U/4G for 8DX and 3U/5G for VT-80. Based on the Yonex literature, both actually have the same weight (85-89.9g), but perhaps because the extra stiffness that 8DX have rather than VT-80 and VT-80 also have the thinnest shaft and newer technology, then I felt that 8DX is head heavier than VT-80. However, I could be wrong, and please do correct me if I am wrong and my judgment was based on my personal feeling about the rackets..... I bought it at the only sport store that supply Yonex racket in the town where I live, and it was AU$250 comes with a bag, a BG-65 string, and a grip. It was coded AS for Australia I guess and hope that is genuine ^^v