Episode was amazing. Throwbacks to Butter's Canadian girlfriend, Craig and Tweek being gay, the gross fatass from the WoW episode, Kyle's dad being a yelp reviewer which led him to becoming a troll. So good.
Cartman was icing on the cake. If the season 19 commentary is any indicator (and I think it is), they don't really have a plan for where they're taking this, but I fully expect it to come full circle in a great way, with Cartman having the biggest impact at the end given how quiet and disconnected his character is to all the shit that's going on right now.