Hope I am posting in the correct area.
One oddity I have noticed in PhpBB.
When you click on the Member list, it shows xxx members per page. I found out through asking questions and playing around, that the number of members showing per page is directly related to how many posts to show per page in the ACP.
I'd personally like them to be independent of each other. I'd like to show 25 members per page when viewing the member list, and 10 posts per page when viewing the topics/posts. Unfortunately, you are tied to posts per page. Whatever is set in the amount of posts per page to show, is the default for how many members to show per page too.