we loved the palza and have not eaten at cosmic rays for a long time( do not even remember it being "called "that , going by the location but it could be I forgot the name) from my foggy recollection CR is definitly fast food where as I think of Plaza as more "sit down" so it depends on what you want and the food was really good at plaza rest. not pavilion ( just wondering if that is the plaza pavilion menu you looked at since they do not really seem that much the same to me)
checked out the 3 mnus myself and I guess they all sound pretty much the same but the "experience" ( if you can call eating a hamburg. an experience lol) is different, course the Plaza Rest. is a bit more expensive also so you are paying for the experience! but the burgers are really good there also