I tried with Chrome and a slow connection, I didn’t encounter this issue. Seemed to me that the posts are displayed after the heights of the images are calculated…
My users didn’t complain about the lack of pagination after migrating from phpbb to discourse, but it’s a small community and the past posts from our long threads (we have some with thousands of posts) aren’t worth the read (they’re like day-to-day stories, sort of).
About the pro and cons of pagination and infinite scrolling, I have read about it and it seems to me that for a forum, infinite scrolling has way more pros than cons.
The major issues to me regarding the pagination are:
- On every page, the first post has more visibility than the others, and the last post has less. Some pagination systems avoided that by having each page’s last post being the next page’s first post.
- On some forums, each user can choose the number of posts displayed on a page. This is an annoying issue because when you open a pagination link from someone else (or a search engine result), you can never know (or you know it will not) if it will land to the correct page.
- The pagination is an arbitrary way to break the flow of a discussion, way which has nothing to do with the discussion content itself. I’m not sure I explain well tough since my English isn’t very good
I personally have no complaints at all regarding Discourse infinite scrolling. The way we share posts URLs and the right scroll behavior work nice.
I feel that most complaints from people about the lack of pagination are nothing but the results of a path dependance.