How does Aion differentiate itself from Everquest

Although I haven't played recently, I played for several months after the initial release. Aion does have some features that set it apart:

• Flight: all characters can "fly" from an early level. In many places, you are only allowed to glide, and your flight time is limited (and can be increased with equipment and potions). This can still make getting around much faster, or at least more entertaining. No mounts are required, but there are "wing" upgrades that get pretty pricey.
• Flying combat: you can fight in the air, and attack others from ground or sky. This gets interesting when you take into account limited flight time - not only do you have to try and win the fight, but you may have to pop potions or maneuver to avoid falling to your death when your wings get tired.
• Crafting system: the addition of NPC work-orders allows you to trade money and craft time for leveling up, and there is always a work-order recipe available for your current level. This avoids the problem of having to find a new recipe and adequate ingredients every time a certain craft skill goes up a few levels. The system also allows any player to reach very high levels in all crafting skills, if they're persistent enough and willing to spend the money. There is also an interesting mechanic that causes random craft attempts to create improved items (but crafting can also fail, depending on skill level). The main downside of the crafting system is that it's very grindy. If you want to max a skill, prepare to spend a lot of time and money.

One of the strongest aspects of Aion is the PvP gameplay. Some things worth mentioning on that topic:

• Fighting in the air, as described above.
• A large, 3-level, dedicated PvP zone, essentially a bunch of floating rocks in space.
• In the PvP zone, there are several fortresses (on each level) that become attackable at semi-random times. The two player factions can own fortresses, and a third, NPC faction (that swoops in in a giant spaceship) will sometimes attack as well. Attacking the fortress involves coordinated groups capturing artifacts that bestow advantages, breaking down fortress defenses and killing NPC defenders, and finally defeating a powerful boss to complete the capture. The faction that captures a fortress gets to use the NPCs there and the dungeon. When I was playing, there were some lag problems due to the quantity of players participating, but this may have improved since then. Even with the lag, it was still a lot of fun.
• A PvP currency used for buying PvP equipment and consumables. This can be gained from defeating enemy players (anywhere) and completing quests and killing monsters in the PvP zone.
• Portals: Each faction has several zones geared more toward PvE and leveling, and these are mostly separated. However, portals appear randomly, but pretty frequently, and these allow players to cross over to the enemy zones and attack. There are a few quests that specifically require the player to go through portals and mess around with the opposing side. Personally, I found this mechanic more interesting than just having shared zones where the factions clash (although that is also present in the PvP zone.

Overall, Aion had some interesting features, and I felt like it did stand out from the crowd more than most games. Castle defense/capture is a great mechanic, and I had missed it from my days playing Ragnarok Online.

What ultimately caused me to stop playing was the level grind. Like many (most?) games originally from Asia, grinding monsters is the main activity, and leveling is pretty slow. There are quests, but the effort to reward ratios get pretty unimpressive as you get closer to the level cap. The PvP zone was fun, but not fast leveling. Organized dungeon raids may be the way to go, I never really got into that while I was playing. I have also seen announcements that say the exp grind has been improved, so my info may be out of date.