I can't think of a single niche where the Vigilance can be useful. In early game, it has to face frigates and so gets wiped out by other frigates. If ion beam, Wolf does it better. If HVD or Mauler, Hound does it better. Many frigates also have 2 small missiles, so it almost forces you to get Harpoon or Pilum or Reaper or Breach. As personally pilotted frigate, there are plenty of better choices. In later game, not only does it still have to face frigates, but it's greatly outranged and slow. Unlike the brawler it can't maneouvre jet to safety and unlike the Centurion, it cannot damper field and hope for the best. In theory it can still work in mid game, throwing missiles out, but they always seem to be amongst the first to get destroyed for me. Perhaps because it has no missle defence unless you equip the medium turret with a PD for some reason. I wonder if that could be a useful role for a Vigilance? But Centurion and Monitor exists. It did get greatly buffed afterall, but it still seems to be a slow/middling speed frigate without a role.