Mate, you are not going to notice a pound or two. It's all in your head and no longer in your wallet. Do you honestly believe you get snappier acceleration if your water bottle is empty as opposed to full?
If you want sharp handling and snappy acceleration, put some money into buying a good quality track frame and then put good quality components on the thing. Buy quality and the weight becomes irrelevant because the acceleration and handling is affected far more by build quality, design, material quality and components.