Ultimately the best answer is "try it and see." Putting weight in front, even if it's low, will slow the steering of the bike. The effect may be less obvious if your bike is low trail instead of standard. Front-loading the weight also puts more weight on the less stressed wheel, which is good. Putting in in the rear may overload the rear wheel and make the front lift when you start pedaling hard up a very steep hill, but your steering won't be affected.
Try it both ways, and see what you like best.