In the months leading up to a race, we actually do most of our training with packs. It helps train your body to burn fat and gives you an idea of how bad you will feel by day 2 in the race. It's also important to do some of your longer training with your teammates. Its not just your body that goes soft after long stretches with little sleep. Make sure you know how each of your teammates reacts to sleep deprivation and fatigue.
Arguments can end races.
We don't know of anyone that has found the ideal gear for all races. Everyone is always looking for newer, lighter, more efficient technology. This is definitely one of the more challenging parts of preparation and has been the source of many long meetings for our teams. Although almost all races will provide you with a minimum equipment list, it is nothing more than that - the absolute minimum required to compete. You will always need more than that.