Its so horribly balanced. Thats the best way to describe this game. From the moment your character is under your control that is the first thing you notice. The "problems" that most people had with Everquest, Anarchy, etc was that the game was unrelenting to newer players. You came into the game and if you didnt read the manual front to back, your lost for the first week or so of playing. Not so with WOW. The game is set up perfectly to take you from a noob to elite in little time and is forgiving when you stumble on that path.
Leveling up is also very well done. Unlike FFXI, which after level 10 became nothing more than a grind to the higher levels, which was not fun in the least bit, the game itself progresses you through the levels. True level 25-45 is something of a grind in itself, as many people have stated, it still retains the ability to keep you playing onward with bigger quests and the always fun and challenging instances.
Instances themselves are worth playing the game for, as by the time you complete the quests for one instance, you are nearly ready for the next level instance. It adds the touch of genius needed to keep players hooked when they reach the most boring stage of the game, and i use boring lightly. By far the best one i have played is Gnomeregan, set deep in the Gnomes lost home-city. Its a level 25-35 instance that is unrelenting towards the end and has a final boss worthy of playing to. When the bombs come out of nowhere and blast you into the air, youll know what i mean. Its fun and challenging, just the way a final boss is supposed to be.
At the time of this writing im only level 36 so i still have alot left to explore. I have heard some complaints that by the end the differences and problems of all classes come out in full. My paladin seems pretty balanced so far though. Also i have heard that doing end game instances and big raids is a pain mainly because of the work and time associated with just getting the people together for them. However, the expansion pack is going to eliminate that problem quite well with the edition of the LFG(looking for group) screen which is already being hailed by most on my server as the best addition to the game since its release. I can agree with that as i too have had problems finding groups for instances in the past, and only havent recently because I found 4 people my level and we do one instance a night, eliminating the need, for now, to even look for another player to join us.
Some have also said that the game is "a MMORPG on easy mode" to which I can agree. I have only recently got the game but I can already see what they mean. Its a bit hard to describe just in writing but it is almost too forgiving, as sometimes it feels like the game is still treating you like a noob. I started on a normal server, because i felt that getting into constant fights with the Horde would prove too difficult at lower levels, and after 20 I am now considering paying to have my character switched to one of the PvP servers because of how challenging it would be. Drawing your sword on a Horde player and having to hope he will engage you is not exciting or very "fantasy-ish." Again i will reference the un-released expansion and quote the creators of the game in saying, the expansion is the hard mode for this game. It will add alot of 60+ content to the game and will constantly be expanded upon, almost exclusively, to make the game more challenging for the more experienced players. Again, its un-released so that goal may fall short, however based on Blizzards current track record with this game, my moneys on it being more than we ever expected.
That all being said, WoW is obviously not a game for everyone, however, it is a good enough game to hook people that never thought they could ever enjoy a game like this. After FFXI and EQ I waited two years to pick this game up, just because of how much i didnt like those two. I finally relented after seeing it for $20 and after the first week i bought 2 of the 60-day game cards. I have only had the game 1 month so far. I have a long way to go before I experience this game fully, and by then BC will be out, and I will surely have that as well. If you arent a fan of the genre, dont let that stop you from giving the game a try. You will at least get your $20 worth. Guaranteed.