I encountered a character with a permanent special effect today which would make my FPS drop from 60 to 30 even when Character Model Quality is set to Lowest.
In the first screenshot below you see my looking at some other character with the model quality set to low. FPS is 63.
In the second I look at the character with the special effect, with model quality set to lowest, and FPS is 35.
How about we finally get an option to turn off all the annoying bling bling on character models, which evidently is also detrimental to FPS? :-)