At the time you could see them more often. Though overall I've found that most people default back to Zeta, Lux and the pre-Lux stage of their relic weapons. They are definitely the most popular relic around and for good reason. I think most people immediately glamour of most of the Blade's weapons, with a few exceptions maybe (GNB/DNC and WHM mostly).
Some tend to become more popular when current sets match the style. Right now I often see the white glowing/burning ultima weapons.