I've noticed something leveling all my other characters that actually took me by surprise a bit and that is the amount of skills I need to keep track of. When I started to read the forums I read all about Hunters being easy and how anyone can play one. In a way I was glad that I choose to play an easier character for my first ever character. In another way I felt like I was going to be the classic huntard no matter how hard I tried because even if I did the slightest thing wrong I would be ridiculed for messing up on something that is so easy.
As time went on with me leveling my hunter I noticed it was indeed easy to level my hunter. The skills I needed to use on a normal basis were few and simple choices. Sting, steady and that was about it, just pound away until I could kill shot and throw in an arcane if need be. So yes, it was kind of stupid easy. The thing is, I was doing it wrong. While no one will actually tell you that because what I mentioned is what makes leveling a hunter so easy. It is just that is it not really effective that way.
After leveling another hunter on another server I noticed that there were skills I got early that I had never used that I was using this time around. It never occurred to me the first time around that concussive shot was such a huge shot that you got early in the game. I looked at it as something that does not do damage, so it is slowing me down by not helping to kill the target faster. In the end, I was dead wrong. Doing it the second time around I open with that shot and my hunter nearly never takes any damage at all, ever. Less healing means less down time and even more so when you are a hunter and can not heal. Eating every battle or two gets annoying after a while.
So I looked back at all my skills and when I got them and how much easier my life would have been if I had used them as intended. The same goes for all the other characters I level now. As I get skills I am not as quick to dismiss something that seems useless just like the concussive shot seemed useless when I first got it.
The conclusion that I came to was that being a hunter is not easy mode. All classes are easy to level. Stupid easy even if you do not try to over do what you are capable of doing. Each class is capable of leveling with limited down time. The difference I noticed is that for some classes it is a breeze and others it requires actual skill if you want to level with limited down time.
A hunter is the one character that while leveling you will need to use a lot of skill to assure limited downtime. Based on that I would have to say that hunters are the hardest class to level if you do it correctly. While doing what I mentioned before you can level easy enough it is not really optimal, not even close.
When it comes to easy for a beginner there are 3 options I would have to say are easy mode when it comes to leveling. A Feral Druid, A Retribution Paladin or a Discipline Priest are the three easiest classes to level with optimum effectiveness that even a complete and total noob would get it right. The reason for that is for each of them to level with optimum effectiveness there are only a few skills you will ever need all the way from 1 to 80.
While there will be other skills that have uses they are not really needed. Like the hunter, me at least, will get concussive shot and possibly overlook its usefulness as a noob, these other classes will never have that problem. Looking at concussive shot it seems useless if you do not know the mechanics of the game and while it will really help a hunter and reduce downtime greatly, it will usually not be used until you learn more about the game.
A Feral Druid can be cat or bear depending on the battle and their skills are fairly straight forward. Not a lot going on there in either cat or bear. Not saying that at end game it is not completely different and more involved but for a leveling purpose a monkey can make it from 1 to 80 without much of an issue. They also have the added benefit of being able to throw a heal on themselves between battle if they need to which greatly reduces down time. When it comes to effective leveling they get an A+ for sure. Downtime should be near 0 if they never over pull.
A Retribution Paladin really has nothing to do outside of auto attacking and judging once in a while. The judge will get you mana if you need it, health if you need that. Unless you are pulling packs and using a lot of spells you will never be below 95% mana and that means you will always be using the judgment to get health which means you will never be below 95% health either. So no down time at all and all those skills are things that would never be missed, like concussive shot was, by a total noob. Another A+, same as before, no over pulls should mean no downtime.
A Discipline Priest kind of surprised me even after knowing a bit about the game. I never thought it would have the type of damage output that it does while being a healer basically. Even a total noob will figure out to drop DoTs on a target from range, to smite or holy fire them and to shield themselves if the mob gets too close. Really, that is all there is to playing a Discipline Priest. My whole leveling process was a joke when it comes to taking damage. You would guess that a clothie would take more damage then others but that shield is over powered and my Priest rarely if ever got hit at all. So having all that healing ability was useless as I never needed to heal myself anyway. Another A+ here but just a note that killing things can be slow but at least you never worry about downtime.
As you see, those three classes in those three specs are easy as sin to level with being they have so few skills that you need to use for optimal performance while leveling and those skills will not be overlooked even by a total and complete noob.
The complete and total use of skills is not needed for any character to level effectively but for some classes, like a hunter, using skills you never really considered using is very important to leveling with as little down time as possible. Don't let anyone ever get away with saying that hutners are easy mode to level until they have leveled the other three I mentioned and then compare them. They might all be easy to an extent but at least those other three will not take nearly 1/3 of their game time eating and drinking like a hunter will.
I understand that longer does not mean harder but longer because you have to eat might mean respawns, might mean adds joining in before you are ready, might mean you end up dying from other things because you needed to stop to eat and drink, something the other classes will rarely ever have to do. So in the case of leveling, longer in this case does equal harder.