If you need immediate medical treatment, you get it. The priority system works - I have never known anyone who has waited for treatment or surgery to the point that it made their condition worse. I have never heard of a cancer patient, and I know way too many, who have not had immediate treatment, for example. Personally, I have experienced some waits but I have also been shuffled ahead if my problem was more serious.
It's also not really the "Canadian system". Each province has a different system, based on the Canada Health Act's five principles - which each province interprets differently, including some provinces who opt to have a mixed public-private system. I pretty much automatically assume someone is an idiot when they talk about the "Canadian system". My experience as a person from Ontario is going to be vastly different than that of someone from Alberta, or Nunavut, or Prince Edward Island.
Regardless, most provinces have been making strides towards addressing wait times and succeeding in many cases. The average ER wait time was down to 3 hours the last time I was in Ontario long enough to need medical treatment. I have spent far longer waiting in a US ER waiting rooms. They really don't differ much in that regard.