The "Thank you...." text should be highlighted somehow, so it draws user's attention faster than menus.

What I do not like on that page is, that the most important information of the page (= "Your comment has been received....") is least highlighted. What reader can see on that page is it is the menu and after a while he realizes there is the information text.

As for the page, I think the user should see the "Your comment...." text first and after that the general layout (the menus). The text should definitely be bigger, perhaps a little bit down (so it appears to be in the middle of the page) and maybe it should be centered and have a different color too, so it attracts the reader's attention.