How credible is neuroeconomics?

Paul Glimcher’s book Foundations of Neuroeconomic Analysis claims that the field of neuroeconomics has made great strides in creating a unified descriptive theory of individual human choice, bringing together positive economics (basically insights from VNM utility theory), neuroscience and psychology. The field was recommended to me by a friend doing a PhD in psychology. If true, the field sounds very useful to study. I don’t have the cognitive science background knowledge to evaluate the credibility of these claims (my economics background is strong), so I have a couple of questions:

  1. Is neuroeconomics founded on solid evidence?

  2. Are there intelligent criticisms of the field?

  3. If neuroeconomics is a useful field to study, what are the best books on the topic?