After its introduction, the ship saw plenty of action during the Brood War. Squadrons of Valkryies effectively destroyed multiple enemy aerospace forces with their H.A.L.O rockets. Unfortunately, it was not enough to turn the tide of battle at the ending point of the war.
Four years later, the Valkyrie phased out in favor of more effective laser batteries and advanced fighter crafts. Some mercenary companies and fringe world militias still use the ships for escorting poorer trade craft through unofficial routes.
For more information see Valkyrie on the parent site.