A psychiatrist is someone who has first qualified as a physician, going to medical school and getting an MD, before then specializing in psychiatry. Thus, one con is that it takes a lot longer and costs a lot more to be a psychiatrist than to be, for example, a clinical psychologist.
A clinical psychologist is an expert in mental health issues who has obtained a professional doctorate in clinical psychology. This doctorate usually also costs money, unless you do one in clinical science, where funding is available (though these are harder to get into).
Two benefits of being a psychiatrist over a clinical psychologist is that psychiatrists earn more money, and are allowed to prescribe drugs. They are thus seen as 'higher status' than psychologists within a hospital setting.
However, much research is showing that drugs are often not the best way of treating mental illness. Cognitive behavioral techniques and psychotherapy can be just as effective, especially at treating underlying causes of a problem, with no side effects (whereas drugs have side effects). The experts in such techniques are clinical psychologists, as psychiatrists often find that their training within the medical model, which sees all problems as originating in biological causes, gets in the way of understanding a patient.
So, a psychiatrist is a high status job, and it takes a lot of work to get there. If you want to be a medical doctor and love biology and chemistry, you might want to consider this route. A clinical psychologist, on the other hand, has a deeper understanding of the emotional and cognitive causes of psychological problems, and so you might enjoy this more if you like talking to people and understanding what is going on inside their heads.