How much red tape is there if one wants to cross an international border?
Now, entering the US is much more aggravating and "tense".
It's not so much that there's lots of red tape, but that the entire experience I perceive as unfriendly and waiting to spring a $5000 fine of you for missing some timing deadline by a few minutes or for having the paperwork innocently imperfectly filled out.
There's also a sense of discoordination. You have to file electronically, and then call the customs office on the phone, giving them a small window for your arrival. You used to just be able to have ATC advise customs of your ETA.
It's to the point where when I need to go to Windsor, Canada, I will often overfly the Windsor airport, cross back into the US, land at Detroit (either Metro or City airport) and rent a car to drive back into Canada. If I just overfly Canada but takeoff and land in the US, it's still a domestic flight and I avoid all the hassle.
I'm sure if I did it more often that it would become routine and seem less arcane and fraught with peril, but I only have occassion to do it a couple times per year, max, and Detroit is really close to Windsor anyway, so it'll stay a mystery for me until I go island hopping the Carribean. That's where a rental car from San Juan, PR or Miami doesn't work as a substitute for a border-crossing.