Yesterday (and today) I spent a LOT of time debugging network packets in our game, Xenocell. I had TORQUE_DEBUG_NET defined and tried to do this "live" meaning via direct connection to a dedicated server.
The client was a DEBUG binary and the server was running release. Fortunately before spending more than 20 hours on finding out why I was getting an invalid checksum right after initiating the connection, I found Stefan Lundmark's thread over at GarageGames.com.