A good amount of customization for how ever you wish to play. There are no class locks, meaning you level and learn skills for weapons as you gain experience with that weapon. May seem basic at first, but as you invest in a weapon type you can really set yourself apart with the different abilities you gain.
No need to create multiple characters (can if you want I guess). Just cycle through weapons and armor, respec some points and you can roll out as a tank, healer, range or melee dps depending on your stats / weapon / armor loadout.