They'd be nice if they were relevant. But only one labor candidate has beenn elected in Quebec in the past 70 years or so.
Actually... so many of their candidates are presumably going to be paper candidates or marxist nutters etc that the opposite is true - they're nice as long as they aren't relevant anyhow.
I would very likely vote for them - there might be some contests that might sufficiently interest me to get me to vote tactical, but not many - but it#d be more of a protest vote than anything else.