What are the pros and cons of practicing these specialties of law?

I'm trying to decide which law schools to apply for. I'm hoping to find a school that specializes in the type of law I want to practice. The only problem is that I'm not exactly sure which one I want. I'm trying to decide between criminal, family, and constitutional law. If there are any lawyers who are currently practicing or have practiced any of these branches of law what would the pros and cons be?

Costitutional law is something virtually nobody practices. Criminal is most interesting but it is hard to get clients to always pay you. family law is rewarding and stressful and makes you question your own familiy situation.