Yes. Animals should definitely be used for experiments. If we look at the big picture, what has more value, a human life or an animal life?
Experiments don't have to necessarily mean harmful medical experiments, either. Experiments to figure out animal intellect, how animals respond to certain stimuli, and observation of their behaviors are perfectly legitimate experiments.
In the end, though, it isn't feasible trying to find large enough groups of people who are willing to undergo dangerous experiments that may end in permanent disfigurement or death. Without animals, science would have a very limited number of subjects to work with. Plus, I can imagine the number of lawsuits would skyrocket.