One thing we have found is how difficult it is to plan out how much we will need to drink/eat during the runs. Inevitably every long run we find we would have been better off with a little more fluid or food. Its a learning process and you have to pay the price for learning those lessons. Hopefully by the time the marathon rolls around we will know what feels best to our bodies.
Hey TW, I notice you have long run entries and only a couple of others per week. Are you not entering all of your runs or are you doing the very scaled down training?