I checked out Cobra most recently on a Thursday night for a visiting DJ. It was for the most part a very pleasant experience, especially by the shady standards of Electro music in Toronto.
The duo selected to open for the main show were Dzeko and Torres, two up and coming Toronto DJs who did a great job warming the crowd up, and kudos to Cobra for letting these guys do their thang!
There was little in terms of trouble/lines to get in, even though there were a decent number of people already inside. That being said the club did not get too overpacked, and the crowd seemed like a mixed level of level headed enthusiasts (paradox?!), typical King St. partygoers, and some slightly older financial district types.
Would definitely return for the Thursday nights or special lineups. Not sure about normal nights.