Rift’s launch seemed very clean and bug-free. Everything seemed to work right off the bat and there have been only a few server restarts that I’ve noticed, and a few updates have been pushed as well with some bug fixes (fixes to issues I did not experience and so can’t really comment on). Compared with the hours of downtime WoW’s servers have endured in the past, hours after the 8 hours of scheduled maintenance, it’s actually refreshing in consideration.
Additionally, I have learned through reading some interviews with the developers that the rifts spawn dynamically. The more players in an area, the more of the random spawns you’ll see. This is good, but the rifts are simply unchallenging with a lot of players. Zergfests just aren’t fun, in my opinion.