Pros: Easy to get into.
Cons: Expensive. Higher USMLE fail rates. Inferior medical education--quality varies greatly depending on the school but in general, not as good as in the U.S. and possibly grossly inadequate. Classes may be taught in a foreign language. Harder to get a good residency in the U.S., esp. in competitive specialties.
Really do your research and carefully consider your options before you go this route. If you do decide to do it, make sure the school you go to is U.S. accreditted. Ross and St.George's are among the more respected foreign med schools. If you really want to be a doctor and can't get into a U.S. school, this route will get you there--just be aware of the downside. You have to decide if it's worth it, and if there's any chance you could get into a U.S. allopathic school, and if you would prefer foreign med school or osteopathic (another route, if allopathic is out of reach).