I think this is easily, bar-none the best pre-launch server stability I've seen in a game in a long time.
I recognize that the login servers have been a pain, especially for those using the NA and EU datacenters. I've had the luxury of playing on the Japanese datacenters from the US and other than the first 30 minutes on early access night, I've been able to log in easily and stay online without disconnects for the entire early access period (logging off and on repeatedly when I needed to go take a break, etc.)
So while I know the team is getting a lot of flack from the community about the login servers, I think there should be a lot of pride taken by the team for maintaining the actual server stability during what is undoubtedly their largest launch ever.
Thanks team and congratulations on a fantastic pinnacle of the storyline, I can't wait for the patch content.