With over ten months of play in Season 3 of Street Fighter V, the argument over which V-Triggers are dominant have started to reach a general consensus on most characters. While there are a few characters that see practical uses of both V-Triggers — some of which are indeed match-up dependent — some characters have clearly superior V-Triggers.
Nash — while having interesting usage of his V-Trigger II — has mostly seen his original V-Trigger used in competitive play. While both V-Triggers have interesting things off of hit confirms, the second V-Trigger suffers from issues past the initial hit confirm, according to VesperArcade. This — when coupled with it requiring one extra bar of V-Meter — causes V-Trigger II to be more of a liability than anything.
Source: VesperArcade