I don't know if this has been brought up but if it has, I apologize.
I play with the 3 level action bar showing. Problem is that every time I log in it resets to the default 1 tier with the BOs pictures below it. Not an issue so much as an annoyance, but the problem is that about half the time, the button to change the action bar to the 3 tier version is off screen. I cannot click it. I play at 1024x768 resolution, and I think that is the default so that should not be the cause. also it doesn't always happen. I can SOMETIMES fix it by going to a higher resolution, and then back to my default but sometimes even at a higher resolution the button is hidden. Problem for me with that is when I change resolutions or ALT-Tab back to STO my comp crashes sometimes (unrelated). Best way to fix this would be let the client keep the setting for the interface as apposed to defaulting to the 1 tier interface every time.