While slightly of a lesser quality than the first Guild Wars, it still KICKS WOW'S @$$.
Factions follows in core Guild Wars footsteps almost to a tee, but has faultered in some ways. Rather than having a small amount of quests at a time, several dozen can be aquired at once, making organization more complicated than it should be. The map still has a lack of cohesion i.e. the city area leads directly into the forest and ocean areas. Also, Factions decided to provide almost all quests with ridiculously high experience rewards, which level you up twice as fast than normal. While you usually reach three-quarters of your maximum level before even leaving the tutorial island, the mainland only has full level enemies, which will decimate you if you are alone.
The good still exists though and is in full force. The Pvp has been upgraded from excellent to phenominal with the addition of the new characters, skills, and 12v12 alliance battles. Also, the various optional challenge missions throughout the campaign provide a fun and varied way to gain the points required to unlock Pvp skills or strengthen your guild's faction. The mission variety changes mission to mission provideing a sense of anticipation to your enjoyment. The best part of both games is definetly the literally thousands of different skill-attribute-profession builds you can make. There is always a different arrangment of skills to match each enviroment which you can manipulate and re-manipulate. Also, the hundreds of "elite skills" in the game can only be captured by killing the boss that holds them, providing even more initiative to explore the game. Titles can also be aquired from completig various tasks. These range from Exploring the map, to winning scores of Pvp matches, to the coveted Drunkard title.
Overall factions is definetly worth spending time on despite its minor faults.