An elected Senate is a bad idea. Take Maine for example, they just elected Democrats to Congress and a Republican to the Senate. How does that make any sense?
Senators in Canada have a small role: review of legislation. They look at it and occasionally send it back to the House of Commons. But they rarely if ever hold back legislation for very long, even when they disagree with it.
Senators in the USA essentially have the same role. However, since they have to get elected every 6 years, they tend to be more active. But they shouldn't be. Their role is to look at legislation approved by the house and make sure there aren't any obvious flaws with it. Bad legislation does get through. A senate is expensive but so is bad legislation that results in court cases. A Senate slows things down, but that can be a good thing in a democracy. We need a sober second thought process.
Canada's Senators may be at times too sober. But I think that is better than being drunk with power.