Yeah, Vanguard being buggy is like saying the ocean is a little moist. I played very lightly during beta (it was a bear that my machine could only barely handle. Built a new PC just to see what the former EQ-fuss was about for release) and there was just a lot of broken stuff. From abilities not triggering, to nodes despawning mid-collection, to falling through the environment, to mobs (and key mobs at that) becoming stuck inside of objects and be unattackable, etc. Add in the chunking issues and it was just a mess. Not to mention that there wasn't really any actual content past level 40 or so at release. Very much like Silithus in WoW was for awhile with no quests, mobs dropped no loot, and there weren't any npcs aside from monsters. They added in content for that stuff eventually, but if you were ahead of the curve near release, you were just grinding or waiting for content to show up. Also, the xp gain and rare mob spawning to complete certain dungeon quests were way out of whack. My static group and I started Dargun's Tomb (giants cave in Thestra built for the early-late 30s) and we were literally only getting xp for every 4th mob or so by the time we finished it, in one session. Had cleared the entire place, but the triggered mob wouldn't spawn to finish up the "Red" quality Dwarven Weapon quest. Started out with most of the place either white or yellow conning. Some dungeon called "Hakrel" was very similar, in that the level range went by too fast to complete the quests and stuff inside.
Had xp been slower overall, maybe some of us bleeding edge folks at release wouldn't have hit the contentless wall before it was rectified. Probably not, though.