"Awesome", yes. It's also going to take about an hour of my full concentration to accomplish. That's also not something I can say about apt-get...
The upgrade procedure takes but minutes in itself. The time you take to save and then write your old configuration files back to /etc and whatnot is on your hands :) Sure, upgrading OpenBSD's core system files isn't as smooth as doing it on f.e. FreeBSD via its package manager, but it's definitely not about hours.