I would like to see a comprehensive table that indicates the relative performance requirements for each plugin.
This is a topic I think all of us who administer WP Multisite networks struggle with: Plugin features vs Site performance (i.e. required server specs, i.e. cost). I wish we could glance at a chart and make a cursory "worth it" / "not worth it" decision *before* we spend a lot of time testing. Furthermore, we all know it is very difficult to remove a feature once it is available to our site admins.
This would also help wpmudev prioritize plugin development. I, for one, think we have plenty of great plugins already available here, yet many of them could be revisited and refined. A table like the one I describe would definitely call attention to those with the most opportunity for improvement.