User blog comment:Dopp/Upcoming change: Removing the divider between the Edit button and Content/@comment-3155630-20110425210851/@comment-1997905-20110425223347

Not to mention that RecentChanges groups edits to the same page to prevent spam, whereas if someone edits a page 20 times, you only see that page in WikiActivity. Furthermore, RecentChanges has a rollback link, which WikiActivity does not.

Simply put: If you want to watch over your wiki effectively, you need to use RecentChanges. WikiActivity falls short in every category.