"New Posts" button hardly ever works for me. When I log in and idle about a bit longer than usual, it automatically logs me out or if I don't have time to read all the new posts and log out for the time being, I lose the option to view those posts at a later time.
Therefore... 'Latest posts' is a great addition to the forum, it's a definite keeper. this way I will still get to view the new posts anytime I wish to view them. Good idea.