what do you mean?
Drop rate was wrong in dvc/soa/loa. I don't know exacly what rate was, but basicaly from my experience deeper dvc was like: 2-4 mobs to drop 1 stone or 1 codex. (Now you need kill like 20+ mobs to get 1 stone or 1codex)
Also lots of full drops. it was 100% sure your party would get a full drop there in like 1h AoE farm.
So they found AFTER 1 month of server up that drop rate was wrong and just changed it.