What load balancing software do you use ?
subwindow: I'm using Pound right now in one large installation, and nginx in another smaller installation, but it still has decent traffic.I definitely prefer Nginx.  It seems much faster, and has definitely given fewer headaches.  It seems like an issue with Pound crops up every few weeks.  My Pound config file is about 600 lines long now, and it is starting to get unmaintainable.