There is very little consistency of the button layout in the various effects. VST effects have a "Play" triangle for preview and Okay/Cancel/Close in a horizontal line across the bottom right. Process effects have a "Preview" button and sometimes this is at the top of a vertical stack of five buttons; other effects split this up and have stacks of 1 and 4 buttons or 2 and 3 buttons.
This is far from a "biggie" but today after using one set of filters for the morning (where Preview was in one place) I almost hit "Okay" on another filter when the Preview was in a different place.
I've been using Audition for ages and am used to this peculiarity--but, for the sake of tidiness and consistency maybe they should look at a standard button layout.