I have been playing since the Open beta started. So here are my pros and cons of WoW

Pros:
Appears to have less lag. Only lag I've seen is when looting but they are already trying to fix that.
Quests. Quests. Quests. My gosh for once I'm excited to do a quest. Quests in HZ seems more like grind quests and have no story or brackground behind them.
Mounts. It's exciting to see that at level 40 you can have a mount. It's something to look forward to.
Spawn rate. Wow.. Mobs spawn fast.. and I mean fast. Even when 10-15 folks are doing the same exact quest as you and trying to kill the same mobs as you the mobs spawn fast enough. THis is not the case in HZ right now as many folks are very frustrated with the spawn rates. My son and wife has gotten bored with hunting :-(
Inventory system. I prefer their inventory system to be more slot based instead of bulk based. Yes it's not realistic but darn it we all know lag is caused by total number of items and not bulk.
The death system is different and has 3 different ways to come back from the dead. There is a bind stone option it just comes with REAL penalties. Bottom line don't die. HZ has no real penalty to death other than astat penalty. I'd prefer and xp and money penalty.
The NPC's are awesome and towns seem ALIVE. There appear to be many NPC's in this game which no real purpose other than to give the towns a look of being alive. HZ towns look like ghost towns. Just look at tazoon. Just a waste of space. In Wow in Stormwind I found a school mistress walking with children. The Children were actually taunting one another. Wow NPC's remind me of Neverwinternights and you get the feeling of real envrionment.
You can play as the enemy. That's sweet. I'd prefer to play as the good guys but it's nice to know on a PvP server your town can be raided by the undead as we all have wished for a year would happen at HZ.

ok enough pros.. let's do a few cons.

Graphics are not as beautitful as HZ but perhaps that's what kills my system.
The interface does not appear to be customizable. How do they know how I like my interface?
General chat tab. OMFG. It's the most annoying part of the game almost enough to drive me to format my hard drive. The game appeals to the younger crowd who seem to get a kick out of insulting everyone and making silly stupid comment. I keep my general chat tab off.
No multiclassing, switching classes. That's annoying.
only 2 primary crafting classes and as a crafter I find that annoying. Crafting is actually TOO easy. Again I think they are seeking a younger audience.
Only certain classes can be played by certain races. Why can't I be an Elven Mage or Paladin? And why can only Dwarves and Elves be hunters? That's annoying but I think I understand that they are trying to follow their Warcraft characters and storylines but still which I could change things up.

ok that's enough for now or I'll be typing for hours.