I ran the Cirque aid station for the PPM for 4 seasons, so here is the view from the other side:
Water bottles are no issue.
As Vomastic noted, use a wide mouth bottle. Trying to pour gatorade into a narrow opening at 13,000ft is a pain in the ass and will guarantee that more ends up on your shoes than it does in your bottle. It also takes a lot longer. Just unscrew the cap as you approach so that you are ready to go.
Come to a complete stop. Pouring water is a lot easier when the target is not moving. It is also a bit faster.
DO NOT CARRY TWO HAND BOTTLES. Nothing was more annoying than having somebody walk up with both hands full, expecting me to unscrew the top for them while 4 other runners wait in line behind them. (If you _have_ to carry two, use a vest so that you have a free hand.)
And if possible, remember to step to the side of the trail to let others pass. The volunteers with the pitchers should be already be on the side and out of the way, but sometimes it gets a bit crazy.
One other tip: as you approach the aid station, yell out either "water" or "gatorade" so that the volunteers know what you want and can direct you to the correct pitcher. Nothing sucks more than finding out that what you want is 10' behind you on the trail.
