Now the button to see the page preview is located in pup up "edit summary" window, which is unexpected location as normally if you edit plain wikitext without this editor you have it bellow edit summary. Sometimes you need to see preview befor saving. E.g. when you add multiple images and you want to see, weather you entered them correctly - in galleries, they are always with namespace name, while in some templates they go sometimes with ns name sometimes no, you want to make sure if the images are not same and you want to controle, if you added right templates.

For these cases, to have one extra click is just a second, for more articles edited during the day its minutes and loss of the time, which can be use to contribute Wikipedia.