Since I tuned up the caching software for Irreal.org I've seen a significant improvement in download speeds. Unfortunately, I've also seen some problems with client-side caching. After I add a new post and reload the site, I see the previous state without the new post. If I delete my browser history, the problem goes away.
Obviously, that's not acceptable so I turned off client side caching. I will monitor the performance on my side to see if this helps things but if you see new problems (or, hopefully, improved performance) please let me know.