It was my understanding that Saiki was the way to go when compared to brissa. Saiki was preferred for "future proofing" because crafting gives it something insane like 50pp. However this was under the context of it being the best 12 star set. AFAIK there are higher rarity sets. So Saiki wouldn't be something you'd hang on to forever.
Ray is being recommended now because PSO2 eventually moves away from it's dependence on set bonuses and cares more for individual stats on armor so you can comfortably mix and match stuff. Also Ray gets an extra slot for ring affixing or something.
If you want my advice stick with Saiki for now if you already have it. We don't really have any content in NA that really demands you to have min maxed gear setups. Heck you can comfortably solo ultimate quests right now with a not even affixed gear. Same with the difficulty above super hard for urgent quests.
I'm not super familiar with PSO2 end game. But I don't think anyone is going to need to worry about having near perfect gear until we're much closer to JP.