I'm following a Runners World sub 3:15 marathon training schedule leading up to Rutland. Yesterday was a sub 1:30 half marathon, at least that is what the training plan had me down for. In the end I managed to cover the distance in 1:30:40s so was relatively happy with that. Got a big pile of excuses as to why I failed to get below 1:30, but hey, I'm more or less on track.
Must point out that I doubt I'll get a sub 3:15 time at Rutland, but aiming high has to be the way to go!
Don't know about energy drinks Jimmy V, I'm thinking of getting a camelbak for this as I always have issues with fluids at events and at least that way I can use my own drink.