Hum. It's looking like my current server setup is not going to work very well in the real world. It's OK for testing and fortunately I carefully kept the server logic separate from the network code so its not too hard to migrate to another solution.
The two major problems I've found are;
Latency - varies from 300ms to 20000ms. Yup, you read that right, a 20 second delay in the worst case. It only happened once or twice but that's still way too often.
Data integrity - occasional random losses of data. Never happens on the dev server, but occasionally on the deployment server a building or two will just vanish without reason. This only happens when there are no players logged on so it's not super serious, but it bodes ill.
The latency issue is the one that annoys me most. I can understand the server taking a few seconds to initially deploy itself, but a constant latency of 10-20secs? What the hell are they doing with my data? Bouncing it off Uranus or something? (mutter, grumble).