I created a feed aggregator with a "load more" button at the end of the posts. When the user clicks on it, loads some more posts and when it is completed, the list of the new posts slides to the top of the window browser with a yellow highlight on the first new post. The previous list is "hidden" because the first post of the new list is on the top. If he wants to see the previous posts, moves the scrollbar up, or down to read the new.
My thought is if it would be better, when the "load more" is clicked, the scrollbar stays as is in the current position user left it and just show the new list below the last post. With this, the previous list is appeared but also some of the new posts(meaning hey it's loaded). There is no sliding effect, no highlighting, and the user continues to read from where he stayed.
In both versions there is a loading animation image.
What is your opinion?