Addictive at fist but later its not!
Once you get to about lvl 30+ you will learn to party in dungeons (dungeons is a place of high level monsters and they are full of them) because you will experience lesser exp when going solo. Once you tried going to dungeons
you won't have any other second thoughts of going out ... Its a paradise of exp!!
Its like going to town then dungeon, going to town then dungeon. See a pattern? And it gets boring going to dungeon seeing the same thing and fighting the same mob everytime! Yes, there's a big world to explore if you ask me to go around the map but what your ultimate goal here is to "level-up". Going around the world will give you a new fresh look and gives you a hype but later on you will grumble on lesser exp you are gaining from them.... so back to dungeon.
P.S. Unless you are used to this kind of game. ^^