Had to wait for over an hour both entering a leaving Copenhagen airport recently, neither of which was much fun. Arrivals seemed very poorly organised, with 3 lines feeding to 5 manned passport control booths, and the staff deciding to send people from 2 of the lines to one booth each, while the third line went to 3 different booths!
Departures weren't much better, with the queue extending far beyond where the barriers end. As much as it pained me to do so, arriving 3 hours before the flight was clearly necessary.
It was clear from talking to the staff that the airport was really struggling to cope with the numbers, and probably needed to put a cap on the number of non-schengen flights they are willing to accept. It's my first experience entering the EU where I've been asked so many questions, which didn't seem to be unique to me. I'm certain this isn't helping the queues.
It's such a poor welcome to a country when it's clear that they can't anticipate demand and provide suitable infrastructure for their visitors. It's quite a contrast to the experience at St Pancras where I've never been waiting more than 30 minutes to get through the whole lot.