I played Vanilla WoW, and I can honestly say that while vanilla WoW was an amazing game in its own right, it was not the EQ killer it was proclaimed to be.
See here's the deal. EQ and vanilla WoW we're not the same genre. This is a distinction that almost every mmorpg player AND publisher fail to recognize.
EQ was the last true traditional RPG-based MMO. By this I mean that the vast majority of your characters combat effectiveness was based off of stats and earned abilities. The player built the character and the character fought the fights. The easiest way to relate to this is "auto-attack."
WoW brought a new genre to the MMO space; Action-RPG. By all rights, it should have been coined a MMOARPG, but Blizzard wanted to compete with the then king of MMOs, so there was no distinction acknowledged. The main difference here is that the characters combat abilities were based much more on the gamers abilities rather than the characters stats.
There IS a fundamental difference in these two styles of mmorpgs.
I choose the stat based style of EQ over the action based style of WoW. And, that's why I play EQ to this very day.