some things to add...

I feel like the people who are saying its too fast are people who powerleveled. Well then, the problem is powerleveling, not that the leveing process is too fast. If you go through normally without powerleveling its pretty standard. My girlfriend, who is a casual player, has been at level 25-30 for like two weeks on her first class.

Also, there are not enough abilities to justify a long ass leveling curve. They streamlined and organized the earning of abilities, which is good, but there isn't enough when you only get something once every 2 levels, and every other time its probably some useless trait that you have no control over anyway (personally I think traits should be made more potent, and then make them toggleable and give you a point budget so you can only toggle some at the expense of others). So effectively you get one fun ability every four levels, and for every other level all you have to occupy yourself in terms of upgrades is gear.

With a slow leveling curve FFXIV is not going to be satisfactory for most people, where every other level you get absolutely nothing. The top level for FFXIV could be 25 and it would make more sense. In that context I think leveling is a little bit too slow, but I can meet in the middle. Leaving it at the current speed and saving the majority of content for end game will make the game more competitive.

IMO, what needs to be done
-nerf powerleveling
-make it so leveling a second class isn't as boring. how this is accomplished I don't really care. But having no quests to do any more is a problem.
-keep the current speed or speed it a up a little bit even.