Originally Posted by
moondog
CA's lounge in CAN is surprisingly nice, particularly the massage chairs, but I wouldn't dream of spending 18 hours in it.
The CA lounge? Wouldn't the OP be using a CZ lounge at CAN?
If CZ gives a hotel for the connection, I would take it to use for a shower (bring your own toiletries in your carry on) and hand luggage storage while exploring the city.