For me, it's not always the quantity of drops, but the quality.
I have ran LOTS of solo SF, SF in party mode, and IV parties. I have yet to see any uni gear drop in the game. I have never seen a unique item drop in a dungeon, ever.
Yesterday, I did get a non-tradable unique laser scanner from a crate in Barbiron. That is the only unique (excluding megaphones) that I have owned.
Yet, I see lots of players with unique gear on. Many have told me that they dropped from a dungeon boss.
I saw unique cyberskins or something drop at asmo once, but was #2 damage so didn't win.
So, I know they're out there. My main concern is that, I feel like I have done endless dungeon runs, and never seen one drop in a dungeon.
I am hoping that "Mother" doesn't just hate me.