I have played nearly every class in Aion to 20 or more. I enjoy all of them for various reasons and all are fun to play while leveling up. I find that the Priest Archetype is the easiest to level initially, the Mage archetype puts out a lot of damage and the Warrior archetype is a nice balance between damage and survivalbility.
The one archetype I have problems with is the Rogue archetype. Assassins are fine. They are a bit hard to level and require frequent resting after kills but they tend to even out after 10 and become a pretty solid leveling class, all in all. They blossom, at level cap, into an awesome fighting force, one that can really do well in PvP and PvE. In short, Assassins are great.
Rangers on the other hand are a wreck at low level. An absolute, frustrating, bang your head against the wall train-wreck. This is completely caused by the Archetype system in Aion. You see, in Aion you start off picking from one of four character Archetypes; Warrior, Mage, Priest or Scout. You level as one of those Archetypes up to level ten, at which point you Ascend and pick your final class. For example, the Warrior Archetype produces either a Gladiator or Templar, the Mage Archetype becomes a Spiritmaster or Sorceror and the Priest Archetype develops into a Cleric or Chanter.
This is all well and good for those Archetypes. Even though their class changes, the core of the class remains the same. Gladiators and Templars are both melee damage dealers with good survivalbility, Sorcerors and Spiritmasters both deal magical damage from range, etc.. There are a few things you must adjust to, but the core of the way the class plays remains the same.
The Scout archetype is different. It produces the Assassin or the Ranger. Whats the big deal you ask? Well one is a
melee character and the other is ranged. Two totally different play-styles. For the first 10 levels, your newly rolled wannabe Ranger will be forced to do nothing but melee. The only skills he will get are all melee based. No bow usage at all.
Then suddenly at level 10 you will become a Ranger and get your first bow skills. The problem is, you don’t get enough, quickly enough. You are instead forced into killing mobs by using the few bow skills that you have and then switching into melee when the mob gets close. You are a weak melee/ranged hybrid for a significant portion of your initial leveling experience. Not enough bow skills to matter and weak melee skills. This makes leveling very difficult. Way more difficult than any of the other classes in Aion, as a matter of fact.
Something needs to be done about this and Rangers brought in line with other classes in the low level game. It is extremely frustrating to level until around level 25-30, which is when you finally accumulate enough ranged skills to make a difference. Until then, Rangers can be a headache to play.
Thankfully, Rangers end up being an extremely powerful class. They can dominate in PvP and PvE at level cap and anyone who goes through the leveling frustration is in for a treat. Rangers and bow classes are normally among the most populous of classes in MMOs, I expect many to be rolled in Aion as well. But, something tells me that we will see few at endgame. The leveling difficulties of the rangers will make many look elsewhere for a class.