2001 Preview of World of Warcraft by Computer Gaming World

The no-no list made me chuckle, You've got to remember these were primarily in comparison to Everquest, which was the leading MMORPG at the time.

• In EQ, you had a loading screen between every zone, sometimes zones were divided into sections with loading screens in between them. Want to move from the starting zone into the city? Loading screen. Want to move from your class trainer to the bank? Loading screen. By comparison, WoW had truly massive areas with seamless transitions.
• Instanced content was not added to EQ until very late in it's life cycle, all content was essentially open world. Does your guild want to raid the Plane of Fear? Too bad, some EU guild cleared it overnight, you're gonna have to wait 12 hours for it to respawn. Aside from a few world bosses, WoW's important progression monsters were all instanced.
• In EQ, downtime was a huge problem, mana and health regenerated very slowly, even outside of combat, meaning that when killing mobs you would inevitably run out of mana or go low on HP, and would have to wait anything up to 15 minutes for it all to regenerate, you spent as much time sitting and waiting as your did actually fighting. WoW introduced food and drink to quickly regenerate health and mana when out of combat, reducing downtime to seconds.
• In EQ you didn't have to eat or drink to live, but being hungry and thirsty did have a negative impact on your stamina, which in turn affected your damage with weapons. Higher level zones were often quite isolated so if you ran out of food it would be a long treck to get some more. WoW obviously has none of this.
• Many of the mobs in the EQ starting zones were literally rats. I remember in Freeport the level 1 enemies were rats, but sometimes there would be level 4 "giant rats" (who were only slightly bigger) mixed in, which at level 1 or 2 you struggled to kill. Seeing a new player running away from a giant rat was a common sight.