I played with Astrox 100zz, it's more flexible than DSZ. Stiffer than Nanoflare 800. Head weight is slightly lighter than NF800 imo. All 3u. I hold at base of grip. Also, Astrox 100zz vibrates are noticeable compared to the other two which have extremely solid feel. Edit: Bought my own real 3u 100zz and it's actually head heavier than DZS and less vibration than originally thought when testing my friends "3u 100zz".