I'm on Cerberus, I haven't experienced any noticeable lag and I were not a victim of the 3102 error during phase 4..
However, now (during Early Access) I've encountered the 90000 (d/c) error and I've constantly been waiting in queue when trying to login (highest queue have been around 250 for me).

I've also been forced to compete over monsters, we've been like 20 people trying to kill the same monsters, which gets rough when there's like 3 of them spawning once per minute or so. And, obviously, had problem with the duty finder like everyone else.

So comparing it to moogle is fine, since it's probably the same story on all the servers right now.