Not only is the reward faster and sense of accomplishment greater, you can also afford to be more selective in your questing, skirting some of the hoarier grinds and longer-distance schleps. The levelling speed has caught up with the number of quests in any particular area, meaning you can be less distracted, allowing yourself to get sucked deeper into the atmospheres and storylines of areas you specifically enjoy.
One of these will now probably be Dustwallow Marsh. A cloying, treacherous swamp for level 35-40 players, notable for its stand-offs between the game's factions - clean-cut Alliance and hardscrabble Horde - it's been substantially revamped in Gods of Zul'Aman. A new neutral town has been added, along with a lengthy quest line involving two new enemy encampments, and some bizarre, Burning Crusade-style steampunk/sci-fi shenanigans at a zeppelin crash-site.
The aim was to plug one of the more barren questing gaps in the progression through the game, and revive an overlooked area. As much as the Marsh needed it, it still seems like an odd choice: the new quests arrive a little later in the levelling curve than you'd like, and it's a tough area, thickly populated with wandering monsters and crossed by unsafe roads. It pays off, though, providing a satisfying crescendo as you approach 40. In keeping with the Burning Crusade philosophy, group quests have been made solo-able, the rewards - whether cash or equipment - are significantly tastier, and the storytelling is far stronger, with more dynamic, memorable quest design. There's more incident, more humour, the world and its NPC inhabitants seem more interlinked and alive.
As was the case with the addition of Outland and the new starting areas for Blood Elf and Draenei in The Burning Crusade, it's so much better that the contrast with the original game is almost a problem. Older areas can feel mean-spirited, while newer ones seem like an embarrassment of riches where simply sneezing at a couple of weak monsters earns you a pile of gold and an awesomely ridiculous pair of barbed shoulderpads. In truth, the game's now pitch-perfect pace and more solid sense of context vastly improves even the slightest of the original zones. Meanwhile, complaining that new zones are too easy, rewarding and fun can only be the crazed bitterness of a veteran of WOW's lean times.
Gods of Zul'Aman also contained a second revolution, as profound as it was quiet. A handful of apparently simple changes to the game's interface have drastically overhauled its usability. Quest-givers are clearly marked on the mini-map, there's a drop down menu allowing speedy searches for certain vendors, trainers and important resources, while quest and gathering items in the world now have a subtle glow. These and a number of other blissfully welcome tweaks have eradicated countless hours of frustration and wasted time, and made it far less overwhelming for new players.
It's still a long, long road, of course, but progress along it is effortless now. That's also thanks in part to the game's community. WOW's enormous popularity and accessibility to younger players was certainly a mixed blessing in its early days, with chances high that you would end up grouping with catastrophically clueless, rude and illiterate adventurers. Although the servers are certainly still thriving, the game's audience has matured along with it. Its player base is now much more knowledgeable and social, and grouping with randoms to run a dungeon is more often than not a pleasant exercise in slotting into each other's groove.