It has a great story, well once you get to Heavensward which is part of the trial. A Realm Reborn is good and has been revamped but is sort of generic. Each class is unique but there are not specs, they play the way they play.
The game is time consuming but rewarding if you enjoy a good fantasy story, it is a Final Fantasy game first and an mmo second. There is plenty of challenging content but gear is quite set for classes for the most part. Meaning you will only be using one type of weapon. Each class has its rotations just like WoW.
Crafting is far better and way more fun and rewarding than Wow atm. There are lots of things to invest your time into. The transmog (glamour) system is not as good as WoW just because of the limited space, granted there is a lot of room and it is only for each character as an individual unless otherwise stated.
Mounts you get as you quest, there is flying which you have to go through the story to unlock and then each zone has little spots for you find find called aether points and some are rewarded by quests by finishing the zone, then you can fly in that zone.
Its a wonderful game and I have just covered some of the basics but it is worth your time investment. It is a lot of fun and the story gets so good , plus plenty of challenges along the way.