I ran with this enabled for a couple of days, and for the most part it improved FPS in situations where I normally experience drops. However, I experienced a strange bug a few times at Volcanic Vents on Galen.

Typically my FPS plummets during those events when there are a lot of other players presernt. But with this feature enabled, I had a different problem: invisible bosses. There were two situations where, when the final boss 'appeared,' it was invisible throughout the entire encounter. I could see the health bar, and I could see that the attacks I was setting off were doing damage, but I never actually saw the target. I just set off attacks in the same direction as everyone else. It also happened once with a Magma Golem at one of the side vents. I've never seen this before, so I wonder if the system wasn't treating the boss as "behind other objects" due to the amount of particle effects going off from all the players who were there.