CrossFit's real downsides are injury risk when coaching is poor or ego takes over, a higher price than a big-box gym, and the intimidation factor for newcomers. Each is largely solved by a well-coached gym that scales workouts, keeps class sizes small, and welcomes beginners rather than testing them.
This is a direct answer from the CrossFit BC coaching team. Short version first, then the detail and the local context for training in Vancouver. If you want the same answer applied to your own situation, a coach will walk through it with you in person.