[Replicant]

I use a search module with a custom search string in it that gives all the new threads, posts and comments in chronological order starting with the newest to the oldest. It works relatively bug free since version 5.1.5. Here is the basic version. I can help you tweak it for your needs. It also displays results based on permissions so if the user is logged in and has access to the closed forums, those new posts will be displayed for them to view.

search?searchJSON={"date":{"from":"1"},"type":["vBForum_Gallery","vBForum_Link","vBForum_Photo","vBForum_Poll","vBForum_Text","vBForum_Video"],"sort":{"relevance":"desc"},"view":"","exclude_type":["vBForum_PrivateMessage"]}

To use it, create a new page in site-builder and add the search module to the page. Edit the search properties in the advanced edit section and replace the search string with this one. Name the page and set the url to whatever you want such as /activity. Now when you navigate to /activity, you will see a page similar to the activity stream in vb4. You can adjust the "date"{"from":1 to however many days you wish to yield more or less results. This module can also be dropped onto a regular page or the front page if you want and will do the same thing. It will auto format for the size column you drop it in.